Implement support for creating and updating fragments from ZIPs

Summary:
This implements support for creating and updating fragments from ZIP files.  It allows you to upload a ZIP via the Files application, create a fragment from it, and have it recursively imported into Phragment.  Updating that folder with another ZIP will recursively create, update and delete files as appropriate.

The logic for creating and updating fragments from files has also been centralized into the PhragmentFragment class.  Directories are also now supported; a directory fragment is simply a fragment that has no patches; thus a directory fragment can be converted to a file fragment by uploading a first patch for it.

Test Plan: Uploaded ZIP files through the interface and saw all of the fragments get created and updated as expected.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T4205

Differential Revision: https://secure.phabricator.com/D7729
Add UI for choosing header color

Summary: See D7731. Fixes T4194.

Test Plan: {F88020}

Reviewers: chad, btrahan

Reviewed By: chad

CC: aran, mbishopim3

Maniphest Tasks: T4194

Differential Revision: https://secure.phabricator.com/D7740
Fix undefined variables in Subversion

Summary: These variables won't be in scope in Subversion.

See: <https://secure.phabricator.com/rP2ff5541fc59c4be7abd733a39e12db8358004f7a>

Auditors: btrahan
Implicitly detect directories when updating a fragment from a ZIP

Summary: This fixes the update-from-ZIP functionality so that it will automatically detect directories in the ZIP that do not have explicit entries.  Some ZIP programs do not create directory entries explicitly, so if we fail to do this then there's no way for users to access the sub-fragments (even though they exist, there is no directory fragment to click through).

Test Plan: Created and updated fragments from a ZIP that had implicit directories in it.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran, staticshock

Maniphest Tasks: T4205

Differential Revision: https://secure.phabricator.com/D7733
Implement viewing versions and downloading patches in Phragment

Summary:
This adds support for viewing individual versions on a fragment as well as comparing versions and downloading diff_match_patch-based patches.

It does not use the side-by-side diff format as while it works for small changes, it quickly becomes impossible to distingush what changes have been made due to the diff_match_patch format.

Test Plan: Clicked on versions and downloaded patches.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T4205

Differential Revision: https://secure.phabricator.com/D7734
Correctly handle downloading ZIP with empty directories in Phragment

Summary: This logic causes an exception because getPHID() is called on a fragment that has no latest version.  This fixes the code so that in this scenario, it returns an empty array (with no path to be added to the ZIP).

Test Plan: Downloaded the ZIP successfully after the patch was applied.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T4205

Differential Revision: https://secure.phabricator.com/D7735
Fix deletion detection when updating based on ZIP

Summary: When the code to update based on ZIP went to look up the child fragments, it explicitly used the paths provided in the ZIP.  This meant that we could never detect omissions because there'd never be a scenario where a child fragment would return but not exist in the ZIP.  To fix this, the query should be using `withLeadingPath` instead of `withPaths`.

Test Plan: Uploaded a ZIP that omitted a file and saw the `deleteFile` get called (by placing debugging output in the code).

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T4205

Differential Revision: https://secure.phabricator.com/D7736
Render deleted files in Phragment as disabled

Summary: This updates Phragment so that fragments that are currently considered deleted have a disabled status and have an additional attribute 'Deleted'.  It also places this effect on versions (in the history controller) that actually involve deleting the file.

Test Plan: Viewed deleted fragments and versions.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T4205

Differential Revision: https://secure.phabricator.com/D7737
Implement "Revert to Version" functionality in Phragment

Summary:
This functionality allows users to revert a fragment to a previous version from the history page.

Reverting a version actually creates a new version pointing at the same file as the version being "reverted" to.  In this sense it acts pretty much like Git and other distributed VCS where once you have published a commit the only way to undo your changes is to create a new commit that reverts those changes.

Test Plan: Reverted a fragment to a version before it was deleted, then reverted it to when it was deleted and saw the new versions have the correct file PHIDs (including null for the deletion).

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T4205

Differential Revision: https://secure.phabricator.com/D7738
Implement snapshots in Phragment

Summary:
Ref T4212.  This implements snapshots in Phragment, which allows you to take a snapshot of a fragment at a given point in time, and download a ZIP of the snapshot as it was in this state.

There's also functionality for deleting and promoting snapshots.  You can promote a snapshot to either the latest version or any other snapshot of the fragment.

Test Plan: Clicked around, took some snapshots, promoted them to different points and deleted snapshots.  Also downloaded ZIPs of the snapshots and saw the right versions coming through for all the files downloaded.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T4205, T4212

Differential Revision: https://secure.phabricator.com/D7741
Implement step for publishing files as fragments to Phragment in Harbormaster

Summary: This adds a build step in Harbormaster for publishing file artifacts as fragments in Phragment.

Test Plan:
Created a build plan with the following steps:

  * Lease Host
  * Upload Artifact
  * Publish Fragment

Ran the build plan against a buildable and saw the fragment get created in Phragment.  Ran the plan again and saw the fragment get updated with a new version.  Modified the file that got uploaded and ran the plan again, checked the history of the fragment, and saw the differences represented as a Diff-Match-Patch patch.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T4205

Differential Revision: https://secure.phabricator.com/D7742
Make taskmaster consumption of failed tasks more FIFO-ey

Summary:
Ref T1049. See discussion in D7745. We have some specific interest in this for D7745, but generally we want to consume tasks with expired leases in roughly FIFO order, just like we consume new tasks in roughly FIFO order. Currently, when we select an expired task we order them by `id`, but this is the original insert order, not lease expiration order. Instead, order by `leaseExpires`.

This query is actually much better than the old one was, since the WHERE part is `leaseExpries < VALUE`.

Test Plan: Ran `EXPLAIN` on the query. Ran a taskmaster in debug mode and saw it lease new and expired tasks successfully.

Reviewers: hach-que, btrahan

Reviewed By: hach-que

CC: aran

Maniphest Tasks: T1049

Differential Revision: https://secure.phabricator.com/D7746
Fix the exception when watching the first commit of a mercurial repo

Summary: Most checks were actually in place, but `ExecFuture` throws a `CommandException` which wasn't taken into account.

Test Plan: look at the first command and no longer saw an exception. Also, other commits worked as well.

Reviewers: richardvanvelzen

Reviewed By: richardvanvelzen

CC: krisbuist, Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7730
Raise a better error for malformed `git ls-tree`

Summary: Ref T4159. See T4159 for discussion.

Test Plan: Faked the error and generated a reasonable error message.

Reviewers: hach-que, btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T4159

Differential Revision: https://secure.phabricator.com/D7744
Show a queue utilization statistic in the Daemon console

Summary:
This came up recently in a discussion with @lifeihuang, and then tangentally with @hach-que. Make it easier for users to get a sense of whether they might need to add more daemons. Although we've improved the transparency of daemons, it's not easy for non-experts to determine at a glance how close to overflowing the queue is.

This number is approximate, but should be good enough for determining if your queue is more like 25% or 95% full.

If this goes over, say, 80%, it's probably a good idea to think about adding a couple of daemons. If it's under that, you should generally be fine.

Test Plan: {F88331}

Reviewers: btrahan, hach-que, lifeihuang

Reviewed By: btrahan

CC: hach-que, lifeihuang, aran, chad

Differential Revision: https://secure.phabricator.com/D7747
plug octocat icon to landing button

Test Plan: look at shiny button

Reviewers: epriestley, chad, #blessed_reviewers

Reviewed By: chad

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7749
Implement "Wait for Previous Builds" build step

Summary: This adds a build step which will block a build from continuing if there are previous builds of the build plan still running.

Test Plan: Configured a build plan with a wait of 60 seconds and a "wait for previous builds", then started a build.  While that was still building, reconfigured the plan to have a wait time of 3 seconds, started it, and saw it move into the "Waiting" status.  When the 60 second build finished, both builds passed.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T1049

Differential Revision: https://secure.phabricator.com/D7745
Provide `phragment.getstate` and `phragment.getpatch` Conduit methods

Summary:
This provides a `phragment.getstate` and a `phragment.getpatch` Conduit method.

`phragment.getstate` - This returns the current state of the fragment and all of it's children.

`phragment.getpatch` - This accepts a base path and a mapping of paths to hashes.  The mapping is for the caller to specify the current state of the files it has.  This returns a list of patches that the caller needs to apply to it's files to get to the latest version.

Test Plan:
Ran the following script in a folder which had content matching a fragment and it's children:

```
#!/bin/bash

STATE=""
for i in $(find ./ -type f); do
    HASH=$(cat $i | sha1sum | awk '{ print $1 }')
    BASE=${i:2}
    STATE="$STATE,\"$BASE\":\"$HASH\""
done
STATE=${STATE:1}
STATE="{$STATE}"

echo '{"path":"tychaia3.zip","state":'$STATE'}' | arc --conduit-uri=http://phabricator.local/ call-conduit phragment.getpatch
```

and I got:

```
{"error":null,"errorMessage":null,"response":[]}
```

I updated one of the child fragments with a new file and ran the script again (patch has been omitted due to it's size):

```
{"error":null,"errorMessage":null,"response":[{"path":"Content\/TitleFont.xnb","hash_old":"4a927d7b90582e50cdd330de9f4b59b0cc5eb5c7","hash_new":"25867504642a3a403102274c68fbb9b430c1980f","patch":"..."}]}
```

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran, staticshock

Maniphest Tasks: T4205

Differential Revision: https://secure.phabricator.com/D7739
Fix error detection for "ls-tree" output

Summary: Fixes T4223. The output of `ls-tree` is partially delimited by spaces
and partially delimited by `\t`. The code I added in D7744 to help debug the
issue in T4159 doesn't work properly for files with 7 or more bytes in their
filesize, because the internals use `%7s`.

Auditors: btrahan
Specify an ssh port for Diffusion when running against the grain

Summary: We run `git` on a different port than 22, so would like to reflect this change in the UI.

Test Plan: Set diffusion.ssh-port in settings, then make sure it's reflected on the Diffusion repository Clone URI.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran, dctrwatson

Differential Revision: https://secure.phabricator.com/D7755