Fix `arc diff --no-ansi`

Summary: Currently, we get an exception on empty %Ls for `arc diff --no-ansi` or similar (see P698).

Test Plan: Ran `arc diff --no-ansi`.

Reviewers: vrana, btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D4624
Don't bail on no effect exception

Summary: The main reason for this is to not exit with 1 when no paths are lintable (which is more success than failure).

Test Plan:
Returned empty array from `buildLinters()`, then:

  $ arc lint
  $ echo $? # 0

Reviewers: epriestley

Reviewed By: epriestley

CC: wez, aran, Korvin

Differential Revision: https://secure.phabricator.com/D4625
Cache results of repository linters

Summary:
The cache key is repository base revision and hash of all modified files.
It isn't perfect in SVN where every file might have a different revision.
It's also suboptimal as just committing or amending changes the cache key even if the files contents weren't modified.
We can improve it later, perhaps by using previous revision and files modified since it.

Test Plan:
Changed granularity of XHPAST linter to repository.
Linted the same repo twice, verified that it was read from cache the second file.
Changed a single file, verified that all files were re-linted.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D4608
Revert "Delete useless code in ArcanistBaseWorkflow"

This reverts commit rARC501e2b7.
We call this method from FB workflow.
I'll commit it again in two weeks.
Fix hg arc land on hg-svn repos

Summary:
arc land on a hg-svn repository would fail because arc land
uses 'hg push -r' to specify which revs to push which is not supported
by hg-svn. Now we just use 'hg push' which, when used against svn, only
pushes the current branch (which happens to be the branch we're trying to land).

We can't use standard 'hg push' for non-svn repos though because when used
against a vanilla hg repo 'hg push' pushes all branches.

Also remove --new-branch from 'hg push' because it's extremely
unlikely that a person wants to create a new branch on the server via
arc land.

Test Plan:
Ran arc land on a normal hg repo, verified it used 'hg push -r'.
Ran arc land on a hg-svn repo, verified it used 'hg push' and it pushed the
correct changes.

Reviewers: epriestley, sid0, dschleimer

Reviewed By: epriestley

CC: bos, aran, Korvin

Maniphest Tasks: T2403

Differential Revision: https://secure.phabricator.com/D4653
Decoupling phpunit test parsing from running and gathering. Should enable third party test engines to reuse common business logic around phpunit without requiring common logic for the typically application-specific running and gathering.

Test Plan: Ran PhpunitTestEngine unit test. Also used refactored PhpunitTestEngine to run phpunit tests.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin, aurelijus

Differential Revision: https://secure.phabricator.com/D4651
Raise a lint warning on array_combine(x, x)

Summary: Suggest array_fuse().

Test Plan:
Unit tests, and:

  $ arc lint --lintall src/unit/engine/phutil/ArcanistPhutilTestCase.php
  >>> Lint for src/unit/engine/phutil/ArcanistPhutilTestCase.php:

     Warning  (XHP37) array_combine() Unreliable
      Prior to PHP 5.4, array_combine() fails when given empty arrays. Prefer
      to write array_combine(x, x) as array_fuse(x).

               252     $callable,
               253     $exception_class = 'Exception') {
               254     return $this->tryTestCases(
      >>>      255       array_combine(array_keys($map), array_keys($map)),
               256       array_values($map),
               257       $callable,
               258       $exception_class);

Reviewers: btrahan, vrana, chad

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D4659
Support PHPUnit 3.7 message changes

Summary: PHPUnit 3.7 now includes user message as well.

Test Plan: Ran phpunit tests

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D4662
Added paths to search for python linters

Summary: Added paths to search for python linters

Test Plan: Linted in ubuntu

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2414

Differential Revision: https://secure.phabricator.com/D4648