Remove horrible old repository edit controller

Summary:
Ref T2231. I didn't port these options over, so they're still supported but have no edit UI:

  - Pull Frequency (confusing/not useful, I think?)
  - Default Owners Path (probably used only by Facebook and only in the E repository)
  - Show user in public repository URL (probably mostly obsolete with hosting?)

We can add those back if users notice, but they seem like the three least useful options so I'm going to see if we can get away with removing them.

Test Plan: Clicked "Edit" from Repositories, got kicked into the nice new Diffusion edit UI instead of the old one.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2231

Differential Revision: https://secure.phabricator.com/D7410
Activate the new Repository creation workflow

Summary:
Ref T2231. This:

  - Activates the new multi-step workflow, and exposes it in the UI.
  - Adds "can create", "default view" and "default edit" capabilities.
  - Provides a default value for `repository.default-local-path` and forces repositories into it by default. It's still editable, but Phabricator gets it correct (for some definition of correct) by default now.

Test Plan: Created some new repositories with the new workflow.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1286, T2231

Differential Revision: https://secure.phabricator.com/D7413
Ship "Repositories" create button to new Diffusion workflow

Summary: Ref T2231. Get rid of the old create controller and make the button go to the new stuff instead. This will eventually get cleaned up more, but I don't have a clear plan for Arcanist Projects yet.

Test Plan: Clicked button, hit new workflow.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2231

Differential Revision: https://secure.phabricator.com/D7414
Add global "push" policy to Repositories

Summary: No editing or view yet, just adds the schema and a policy default. Part of D7391.

Test Plan: `bin/storage upgrade`

Reviewers: hach-que, btrahan

Reviewed By: hach-que

CC: aran

Maniphest Tasks: T2230

Differential Revision: https://secure.phabricator.com/D7415
Add hosting, serving, and push policy options to repository edit

Summary:
Basically straight from D7391. The differences are basically:

  - Policy stuff is all application-scope instead of global-scope.
  - Made a few strings a little nicer.
  - Deleted a bit of dead code.
  - Added a big "THIS DOESN'T WORK YET" warning.

Test Plan: See screenshots.

Reviewers: hach-que, btrahan

Reviewed By: hach-que

CC: aran

Maniphest Tasks: T2230

Differential Revision: https://secure.phabricator.com/D7416
Accept and route VCS HTTP requests

Summary:
Mostly ripped from D7391, with some changes:

  - Serve repositories at `/diffusion/X/`, with no special `/git/` or `/serve/` URI component.
    - This requires a little bit of magic, but I got the magic working for Git, Mercurial and SVN, and it seems reasonable.
    - I think having one URI for everything will make it easier for users to understand.
    - One downside is that git will clone into `X` by default, but I think that's not a big deal, and we can work around that in the future easily enough.
  - Accept HTTP requests for Git, SVN and Mercurial repositories.
  - Auth logic is a little different in order to be more consistent with how other things work.
  - Instead of AphrontBasicAuthResponse, added "VCSResponse". Mercurial can print strings we send it on the CLI if we're careful, so support that. I did a fair amount of digging and didn't have any luck with git or svn.
  - Commands we don't know about are assumed to require "Push" capability by default.

No actual VCS data going over the wire yet.

Test Plan:
Ran a bunch of stuff like this:

  $ hg clone http://local.aphront.com:8080/diffusion/P/
  abort: HTTP Error 403: This repository is not available over HTTP.

...and got pretty reasonable-seeming errors in all cases. All this can do is produce errors for now.

Reviewers: hach-que, btrahan

Reviewed By: hach-que

CC: aran

Maniphest Tasks: T2230

Differential Revision: https://secure.phabricator.com/D7417
Prepare to route VCS connections through SSH

Summary:
Fixes T2229. This sets the stage for a patch similar to D7417, but for SSH. In particular, SSH 6.2 introduced an `AuthorizedKeysCommand` directive, which lets us do this in a mostly-reasonable way without needing users to patch sshd (if they have a recent enough version, at least).

The way the `AuthorizedKeysCommand` works is that it gets run and produces an `authorized_keys`-style file fragment. This isn't ideal, because we have to dump every key into the result, but should be fine for most installs. The earlier patch against `sshd` passes the public key itself, which allows the script to just look up the key. We might use this eventually, since it can scale much better, so I haven't removed it.

Generally, auth is split into two scripts now which mostly do the same thing:

  - `ssh-auth` is the AuthorizedKeysCommand auth, which takes nothing and dumps the whole keyfile.
  - `ssh-auth-key` is the slightly cleaner and more scalable (but patch-dependent) version, which takes the public key and dumps only matching options.

I also reworked the argument parsing to be a bit more sane.

Test Plan:
This is somewhat-intentionally a bit obtuse since I don't really want anyone using it yet, but basically:

  - Copy `phabricator-ssh-hook.sh` to somewhere like `/usr/libexec/openssh/`, chown it `root` and chmod it `500`.
    - This script should probably also do a username check in the future.
  - Create a copy of `sshd_config` and fix the paths/etc. Point the KeyScript at your copy of the hook.
  - Start a copy of sshd (6.2 or newer) with `-f <your config file>` and maybe `-d -d -d` to foreground and debug.
  - Run `ssh -p 2222 localhost` or similar.

Specifically, I did this setup and then ran a bunch of commands like:

  - `ssh host` (denied, no command)
  - `ssh host ls` (denied, not supported)
  - `echo '{}' | ssh host conduit conduit.ping` (works)

Reviewers: btrahan

Reviewed By: btrahan

CC: hach-que, aran

Maniphest Tasks: T2229, T2230

Differential Revision: https://secure.phabricator.com/D7419
Route some VCS connections over SSH

Summary:
  - Add web UI for configuring SSH hosting.
  - Route git reads (`git-upload-pack` over SSH).

Test Plan:
  >>> orbital ~ $ git clone ssh://127.0.0.1/
  Cloning into '127.0.0.1'...
  Exception: Unrecognized repository path "/". Expected a path like "/diffusion/X/".
  fatal: Could not read from remote repository.

  Please make sure you have the correct access rights
  and the repository exists.
  >>> orbital ~ $ git clone ssh://127.0.0.1/diffusion/X/
  Cloning into 'X'...
  Exception: No repository "X" exists!
  fatal: Could not read from remote repository.

  Please make sure you have the correct access rights
  and the repository exists.
  >>> orbital ~ $ git clone ssh://127.0.0.1/diffusion/MT/
  Cloning into 'MT'...
  Exception: This repository is not available over SSH.
  fatal: Could not read from remote repository.

  Please make sure you have the correct access rights
  and the repository exists.
  >>> orbital ~ $ git clone ssh://127.0.0.1/diffusion/P/
  Cloning into 'P'...
  Exception: TODO: Implement serve over SSH.
  fatal: Could not read from remote repository.

  Please make sure you have the correct access rights
  and the repository exists.

Reviewers: btrahan

Reviewed By: btrahan

CC: hach-que, aran

Maniphest Tasks: T2230

Differential Revision: https://secure.phabricator.com/D7421
Serve Git reads over HTTP

Summary: Mostly ripped from D7391. No writes yet.

Test Plan: Ran `git clone` against a local over HTTP, got a clone.

Reviewers: btrahan, hach-que

Reviewed By: hach-que

CC: aran

Maniphest Tasks: T2230

Differential Revision: https://secure.phabricator.com/D7423
Serve Git reads over SSH

Summary: Like D7423, but for SSH.

Test Plan: Ran `git clone ssh://...`, got a clone.

Reviewers: btrahan

Reviewed By: btrahan

CC: hach-que, aran

Maniphest Tasks: T2230

Differential Revision: https://secure.phabricator.com/D7424
Serve git writes over SSH

Summary: Looks like this is pretty straightforward; same as the reads except mark it as needing PUSH.

Test Plan: Ran `git push`, pushed over SSH to a hosted repo.

Reviewers: btrahan

Reviewed By: btrahan

CC: hach-que, aran

Maniphest Tasks: T2230

Differential Revision: https://secure.phabricator.com/D7425
Enable "SSH Keys" auth panel unconditionally

Summary: We've had support for this for a long time, but it was conditional on config. Since it more-or-less actually does something now, just enable it unconditionally.

Test Plan: Settings -> SSH Public Keys

Reviewers: btrahan

Reviewed By: btrahan

CC: hach-que, aran

Maniphest Tasks: T2230

Differential Revision: https://secure.phabricator.com/D7426
Don't pull updates for repositories marked as hosted

Summary:
  - Don't try to pull hosted repos.
  - Also, fix the `--verbose` + `--trace` interaction for `bin/repository`.
  - Also, fix a couple of unit tests which got tweaked earlier.

Test Plan:
  $ ./bin/repository pull GTEST --verbose
  Pulling 'GTEST'...
  Repository "GTEST" is hosted, so Phabricator does not pull updates for it.
  Done.

Reviewers: btrahan, hach-que

Reviewed By: hach-que

CC: aran

Maniphest Tasks: T2230

Differential Revision: https://secure.phabricator.com/D7427
Distinguish between empty and unparsed commits in Diffusion

Summary:
Fixes T3416. Fixes T1733.

  - Adds a flag to the commit table showing whether or not we have parsed it.
  - The flag is set to `0` initially when the commit is discovered.
  - The flag is set to `1` when the changes are parsed.
  - The UI can now use the flag to distinguish between "empty commit" and "commit which we haven't imported changes for yet".
  - Simplify rendering code a little bit.
  - Fix an issue with the Message parser for empty commits.
  - There's a key on the flag so we can do `SELECT * FROM repository_commit WHERE repositoryID = %d AND importStatus = 0 LIMIT 1` soon, to determine if a repository is fully imported or not. This will let us improve the UI (Ref T776, Ref T3217).

Test Plan:
  - Ran `bin/storage upgrade -f`.
  - Created an empty commit.
  - Without the daemons running, ran `bin/repository pull GTEST` and `bin/repository discover GTEST`.
  - Viewed web UI to get the first screenshot ("Still Importing...").
  - Ran the message and change steps with `scripts/repository/reparse.php`.
  - Viewed web UI to get the second screenshot ("Empty Commit").

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T776, T1733, T3416, T3217

Differential Revision: https://secure.phabricator.com/D7428
Add an "importing" state to repositories and clean up the UI

Summary:
Fixes T3217. Ref T776. Ref T1493. Broadly, this introduces a mechanism which works like this:

  - When a repository is created, we set an "importing" flag.
  - After discovery completes, we check if a repository has no importing commits. Basically, this is the first time we catch up to HEAD.
  - If we're caught up, clear the "importing" flag.

This flag lets us fix some issues:

  - T3217. Currently, when you import a new repository and users have rules like "Email me on every commit ever" or "trigger an audit on every commit", we take a bunch of publish actions. Instead, implicitly disable publishing during import.
  - An imported but un-pulled repository currently has an incomprehensible error on `/diffusion/X/`. Fix that.
  - Show more cues in the UI about importing.
  - Made some exceptions more specific.

Test Plan:
This is the new screen for a completely new repo, replacing a giant exception:

{F75443}

  - Created a repository, saw it "importing".
  - Pulled and discovered it.
  - Processed its commits.
  - Ran discovery again, saw import flag clear.
  - Also this repository was empty, which hit some of the other code.

This is the new "parsed empty repository" UI, which isn't good, but is less broken:

{F75446}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran, hach-que

Maniphest Tasks: T3607, T1493, T776, T3217

Differential Revision: https://secure.phabricator.com/D7429
Make Phabricator clone bare git repositories

Summary:
This doesn't really impact anything very much, but is a little cleaner than cloning repositories with a working copy. It's somewhat important for allowing pushes, because you can't push to a checked-out branch.

Mercurial has a similar option (`--noupdate`) but leave that alone for now.

The origin stuff was mostly for sanity/explicitness purposes -- I believe it's safe to remove in all non-ridiculous cases. Git fails with it in bare repositories (it automatically creates an `origin`, but doesn't create the local refs for it, or something).

Test Plan: Nuked a repo, re-cloned it, pulled and updated it several times. Browsed both bare and non-bare repos in Diffusion.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2230

Differential Revision: https://secure.phabricator.com/D7430
Reject SCP-style URIs with explicit protocols in Diffusion

Summary:
Fixes T3619. These URIs are valid:

  git@domain.com:/path        (Git SCP-style implicit SSH)
  ssh://git@domain.com/path   (Explicit SSH)

This URI, arrived at by adding "ssh://" to the front of an SCP-style URI, is not:

  ssh://git@domain.com:/path

Detect URIs in this form and reject them. See T3619.

Test Plan:
{F75486}

Also set some valid URIs.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T3619

Differential Revision: https://secure.phabricator.com/D7431