Fix markup in documentation for arcanist lint engine

Summary: Fixed wrong markup which was 1 space instead of 2

Test Plan: I couldn't test it as I don't know how to build documentation

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7587
Make ScriptAndRegexLinter available to ConfigurationDrivenLintEngine

See: <https://github.com/facebook/arcanist/pull/118>

Reviewed by: epriestley
Upgrade C# linter to support linting multiple files at a time

Summary:
This upgrades `cslint` to support linting multiple files at a time.  As this required a backwards-incompatible to `cslint`, I've added a SUPPORTED_VERSION constant which can be used to detect these kinds of breaking changes in the future (and prompt users to upgrade the `cslint` they have in their repository).

The reason for this upgrade is mainly around running `arc lint --everything`, where there are significant performance benefits gained when bulk linting lots of files per command execution.

Test Plan: Upgraded `cslint` in the Tychaia repository and ran `arc lint --everything --trace`.  Saw a substantially less number of executions happening for linting and all of the results came through as expected.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran, waynea

Differential Revision: https://secure.phabricator.com/D7599
Set limit for execution in C# linter

Summary: This sets the limit for future execution in the C# linter to 8.  See D7606 for more information.

Test Plan:
Ran

```
arc lint --everything --trace --never-apply-patches --output json
```

and saw it only run 8 commands at once.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7607
Improve exception raised when an event listener fails to load

Summary: See IRC. The failing class might not be the listener itself.

Test Plan:
  $ arc list
  ERROR: Failed to load event listener 'depr': Failed to load class or interface 'depr': the class or interface 'depr' is not defined in the library map for any loaded phutil library. If this symbol was recently added or moved, your library map may be out of date. You can rebuild the map by running 'arc liberate'. For more information, see: http://www.phabricator.com/docs/phabricator/article/libphutil_Libraries_User_Guide.html

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D7616
ArcanistGitAPI: remove a bogus comment

See: <https://github.com/facebook/arcanist/commit/628de7d7a15cd7b5737515ec2831b3b4c3f601a5#commitcomment-4675543>

This comment is indecipherable even if it originally meant something.

Reviewed by: epriestley
ArcanistGitAPI: document a git ls-files bug

When a submodule is ignored (ignore=all in .gitconfig),

  $ git ls-files -m

fails to exclude the submodule from the listing. Other commands like

  $ git diff-index --name-only HEAD

exclude it just fine.

See: <https://github.com/facebook/arcanist/pull/120>

Reviewed by: epriestley
ArcanistGitAPI: replace 'ls-files -m' with diff-files

As documented,

  $ git ls-files -m

fails to exclude ignored submodules. Replace it with an equivalent:

  $ git diff-files --name-only

which does not suffer from this defect.

See: <https://github.com/facebook/arcanist/pull/121>

Reviewed by: epriestley
Fix issues in C# unit test engine

Summary: This fixes a few issues in the C# unit test engine.  It fixes tests sitting in subdirectories not being tested correctly (the location of both the test assembly and the results file would be wrong).  It also fixes a very strange issue where xUnit.NET seems to not output the resulting XML file when it executes; in this case we just retry running the test until the XML file appears after completion (and eventually it works).

Test Plan: Ran `arc unit --everything` and `arc unit --everything --no-coverage` and verified that it's all reliably working.

Reviewers: epriestley, #blessed_reviewers, hach-que

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7594
Remove debugging output from xUnit.NET test engine

Summary: This just removes the `print "Discovered test .."` code in the xUnit.NET unit test engine.  If users need to diagnose what tests are being debugged, it can be found out with `--trace` and observing what build commands are invoked.

Test Plan: Ran `arc unit --everything` and didn't see the message any more.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7639
Add output-json option to arc feature

Summary:
The current format of arc feature is not very friendly to parsing.  This adds a json output
format.

Test Plan: Run the command and ensure output is valid

Reviewers: lifeihuang, #blessed_reviewers, epriestley

Reviewed By: epriestley

CC: epriestley, aran, Korvin

Differential Revision: https://secure.phabricator.com/D7647
Update C# tools unit test engine to work

Summary: This updates the C# tools unit test engine (the derived version of xUnit.NET test engine that supports code coverage) to work after the updates in D7594.

Test Plan:
Switched the test engine from 'XUnitTestEngine' to 'CSharpToolsTestEngine' and ran `arc unit --everything`.  The results were identical except that code coverage was provided.

Tested on Linux; will update or comment based on whether it works on Windows as well.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7640
Fix working copy binding powers in weird edge cases

Summary:
Fixes T1277. The rules we use to figure out the root of the working copy get a bunch of edge cases wrong right now. A particularly troublesome one is when a user has a `/.arcconfig` or `/home/.arcconfig` or similar, which raises a completely useless and confusing error message (T1277).

Rewrite these rules to get all the edge cases correct and do reasonable things in the presence of stray `.arcconfig`. There are a bunch of comments, but basically the algorithm is:

  - From the top, go down one directory at a time until we find ".svn", ".git", or ".hg".
  - In Subversion, keep going down looking for ".arcconfig". In Git and Mercurial, look for ".arcconfig" only in the same directory.
  - Now that we've figured out the VCS root (where the ".vcs" directory is) and the project root (where the ".arcconfig" file is, if it exists), build an identity.

This logic was also spread across three different places. Consolidate it into one and add some logging so we can figure out what's going wrong if users run into trouble.

Test Plan:
  - Ran VCS (`arc list`) and non-VCS (`arc help`) commands in Git, Mercurial, and Subversions roots and subdirectories. Also ran them in non-VCS directories. Ran them with and without .arcconfig. All the outputs seemed completely reasonable.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1277

Differential Revision: https://secure.phabricator.com/D7686
Make sure no one ever misunderstand the "unkonwn symbol" lint message ever again

Summary: A lot of new contributors don't resolve this. Make it easier to resolve, more comprehensive, and more explicit about not being ignorable.

Test Plan:
  >>> orbital ~/devtools/arcanist $ arc lint
  >>> Lint for src/lint/linter/ArcanistPhutilLibraryLinter.php:

     Error  (PHL1) Unknown Symbol
      Use of unknown class 'BlerpBarp'. Common causes are:

        - Your libphutil/ is out of date.
          This is the most common cause.
          Update this copy of libphutil: /INSECURE/devtools/libphutil

        - Some other library is out of date.
          Update the library this symbol appears in.

        - This symbol is misspelled.
          Spell the symbol name correctly.
          Symbol name spelling is case-sensitive.

        - This symbol was added recently.
          Run `arc liberate` on the library it was added to.

        - This symbol is external. Use `@phutil-external-symbol`.
          Use `grep` to find usage examples of this directive.

      *** ALTHOUGH USUALLY EASY TO FIX, THIS IS A SERIOUS ERROR.
      *** THIS ERROR IS YOUR FAULT. YOU MUST RESOLVE IT.

               181               "*** THIS ERROR IS YOUR FAULT. YOU MUST RESOLVE IT.");
               182
               183             if (false) {
      >>>      184               new BlerpBarp();
               185             }
               186           }
               187         }
  >>> orbital ~/devtools/arcanist $

Reviewers: btrahan, chad

Reviewed By: chad

CC: aran

Differential Revision: https://secure.phabricator.com/D7752
Make sure the local arc config directory exists on `ArcanistWorkingCopyIdentity::writeLocalArcConfig`

See: <https://github.com/facebook/arcanist/pull/126>

Reviewed by: epriestley
Merge remote-tracking branch 'upstream/master'