Fix `arc unit` when running from non-root directory

Summary:
`$this->getPaths()` gives us paths relative to repository root.
We resolve them relative to cwd.

Test Plan: [src] `arc unit difference`

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Koolvin

Differential Revision: https://secure.phabricator.com/D2634
Move files in Arcanist one level up

Summary:
- `kill_init.php`
- Manually change library map.
- Manually rename `/data/` test dirs.
- [src/lint/linter] `git mv base/ArcanistLinterTestCase.php __tests__/`
- `arc liberate`

Test Plan: Browse around to make sure I like it better, especially `repository/api`, and `workflow`.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Koolvin

Maniphest Tasks: T1103

Differential Revision: https://secure.phabricator.com/D2637
Render chevrons and carets in lint output for messages without "original" text

Summary:
If a message has only "line", or "line" and "char", we don't point out the location in the context block.

When a message includes "line", show chevrons on the line.
When a message includes "line" and "char", show chevrons on the line and a caret on the next line.

Test Plan: Ran regex linters to capture line, line+char, and normal linters to capture everything. Output appeared sane.

Reviewers: csilvers, vrana, btrahan

Reviewed By: csilvers

CC: aran

Differential Revision: https://secure.phabricator.com/D2642
Examine only HEAD in amend workflow

Summary: We don't support `git rebase -i` or other magic in `arc amend` so we can examine just HEAD which we always amend.

Test Plan: `arc amend` on a branch with two commits.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Koolvin

Differential Revision: https://secure.phabricator.com/D2643
Define interface for lint renderers

Summary:
It makes me nervous.

Also move them to the dir.

Test Plan:
`arc lint`
`arc lint --output json`

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Koolvin

Differential Revision: https://secure.phabricator.com/D2644
Remove unused variable
Fix context for lint errors at top of file in JSON renderer
Fix comment
Add "--conduit-timeout" to `arc` and modernize argument parsing

Summary:
We added "repeat" to PhutilArgumentParser a while ago, so we can modernize the rest of the argument parsing (allow multiple --load-phutil-library flags).

Add a "--conduit-timeout" flag to allow users to set the timeout. See D2602.

Test Plan:
  $ arc diff --conduit-timeout=0.01
  Exception
  [cURL/28] <CURLE_OPERATION_TIMEOUTED> The request took too long to complete.
  (Run with --trace for a full exception trace.)
  $ arc diff --conduit-version 33
  Exception
  ERR-BAD-VERSION: Your 'arc' client version is '33', which is newer than the server version, '5'. Upgrade your Phabricator install.
  (Run with --trace for a full exception trace.)
  $ arc diff --conduit-uri http://derp.derp/
  Usage Exception: YOU NEED TO INSTALL A CERTIFICATE TO LOGIN TO PHABRICATOR

  You are trying to connect to 'http://derp.derp/api/' but do not have a certificate installed for this host. Run:

        $ arc install-certificate

  ...to install one.
  $ arc diff --load-phutil-library src --load-phutil-library ../phabricator/src --trace
  Loading phutil library '0' from '/INSECURE/devtools/arcanist/src'...
  Loading phutil library '1' from '/INSECURE/devtools/phabricator/src'...

Reviewers: phleet, vrana, btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D2603
Use project root instead of library root in unit engine
Improve syntax error output from "arc liberate"

Summary:
Currently, when a file has a syntax error and you run "arc liberate", the symbol analyzer will fail and throw, which will make the mapper fail and throw, which will make arc fail and throw. This gives you a stack trace pile three scripts deep which is a giant pain to analyze visually.

Instead, raise a clear message.

Test Plan: Ran "arc liberate" with a syntax error. Got useful diagnostic output instead of 30 pages of stack mess.

Reviewers: vrana, btrahan

Reviewed By: vrana

CC: aran

Differential Revision: https://secure.phabricator.com/D2659
Support mutable history in mercurial for arc diff and arc amend

Summary:
This adds basic support for mutable history for arc diff and arc amend for
mercurial. This is purely opt-in (so it shouldn't affect anyone who doesn't want
this feature) by explicitly setting

    "immutable_history" : false

in arc configuration.

This also fixes another instance of weird behaviour for multiple heads - the
first instance was fixed here:
https://github.com/facebook/arcanist/pull/28

Test Plan:
without "immutable_history" turned on)>

When ##arc diff## produces an update diff, it should list only commits that are
ancestors of the current revision - not ones from other heads.

Reviewers: epriestley

CC: csilvers, aran, Koolvin

Differential Revision: https://secure.phabricator.com/D2654
Merge pull request #35 from phleet/hg-mutable

Support mutable history in mercurial for arc diff and arc amend
Allow skipping unit tests and support 'repeat' workflow arguments

Summary:
We run all tests before deploy but some of them are expected to fail.
We need to skip them.
It can be useful also for someone else.

I don't propagate this to `arc diff` as that would be much more complicated - we would need a new state 'partially skipped'.

The 'path' argument needs to be a file, skipping whole dirs is not supported.
The 'path' argument is in fact engine specific and engines can support format like 'Class::testMethod' but I didn't bother to document it to not confuse people.

Test Plan:
`arc unit --skip test.php`
`arc unit --skip ../src/test.php`

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D2673
Rough cut of hgdaemon

Summary:
This need a bunch of work, but is a sort of minimum viable product for the hgdaemon.

The two ProtocolChannels implement the client and server halves of the protocol.

The Server implements the server logic, the Client implements the client logic.

Test Plan: Launched a server and client on the same repo, got hg output in ~2-3ms instead of 100ms+.

Reviewers: csilvers, btrahan, vrana

Reviewed By: csilvers

CC: aran

Differential Revision: https://secure.phabricator.com/D2665
Minor, make amendCommit() prototypes match up to avoid E_STRICT.
Remove support for skipping tests

Summary: Almost revert D2673 but leave the support for 'repeat'.

Test Plan: `arc help unit`.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D2689
Pass for phutil test that was expected to fail and skip

Summary:
I just hope that we will not create `ArcanistPhutilTestCaseTestCaseTestCase`.

Also fix a copy/paste error (@edward's this time).

Test Plan: `arc unit`

Reviewers: epriestley

Reviewed By: epriestley

CC: edward, aran, Korvin

Differential Revision: https://secure.phabricator.com/D2692
Use .^ instead of HEAD^ for mercurial

Summary:
##arc amend## in a mercurial repo was failing with this message

    Usage Exception: Commit 'HEAD^' is not a valid Mercurial commit identifier.

mercurial's .^ is about the same thing as git's HEAD^

Test Plan:
##arc amend## in a mercurial repo with ##"immutable_history" : "false"## in the
##.arcconfig##.

Reviewers: epriestley

Reviewed By: epriestley

CC: vrana, aran, Korvin

Differential Revision: https://secure.phabricator.com/D2690
Merge pull request #36 from phleet/hg-head-pull

Use .^ instead of HEAD^ for mercurial