Refactor getWorkingCopyStatus() into getUncommittedStatus() and getCommitRangeStatus()

Summary:
See discussion in D4049.

The getWorkingCopyStatus() method gets called from requireCleanWorkingCopy() in a lot of places, which triggers resolution of the base of the commit range. This is unnecessary; we do not need to examine the base commit in order to determine whether the working copy is dirty or not. This causes problems, in D4049 and elsewhere (we currently have a lot of fluff calls to setDefaultBaseCommit() in workflows which need to call requireCleanWorkingCopy() but do not ever use commit ranges, such as `arc patch`). This is mostly an artifact of SVN, where the "commit range" and "uncommitted stuff in the working copy" are always the same.

  - Split the method into two status methods: getUncommittedStatus() (uncommitted stuff in the working copy, required by requireCleanWorkingCopy()) and getCommitRangeStatus() (committed stuff in the commit range).
  - Lift caching out of the implementations into the base class.
  - Dirty the cache after we commit.

This doesn't do anything useful on its own and creates one caching problem (`commitRangeStatusCache` is not invalidated when the commit range changes because of `setBaseCommit()` or similar) but I wanted to break things apart here. I won't land it until there's a more complete picture.

This creates a minor performance regression in git and hg (we run less stuff in parallel than previously) but all the commands should be disk-bound anyway and the regression should be minor. It prevents a larger regression in `hg` in D4049, and lets us do less work to arrive at common error states (dirty working copy). We can examine perf at the end of this change sequence.

Test Plan: Ran unit tests, various `arc` commands.

Reviewers: vrana

Reviewed By: vrana

CC: aran

Differential Revision: https://secure.phabricator.com/D4095
Remove ArcanistRepositoryAPI::setDefaultBaseCommit()

Summary:
This method is used in three cases:

  # For unit tests, to set the range to 'HEAD^' or '.^' in an agnostic way.
  # For "amend", to set the range to the commit to be amended (also 'HEAD^' or '.^').
  # For "patch" and "upgrade" so we don't fail just because there's an invalid "base" rule somewhere in the config when doing clean-working-copy tests.

For cases (1) and (2), introduce an "arc:this" rule to mean "the current commit". For case (3), remove the call; it is no longer necessary to check the commit range in order to do tests for the working copy state after D4095.

Test Plan: Ran unit tests, "arc upgrade", "arc patch", "arc amend".

Reviewers: vrana

Reviewed By: vrana

CC: aran

Differential Revision: https://secure.phabricator.com/D4096
Refactor commit ranges and base commit handling

Summary:
See D4049, D4096.

  - Move commit range storage from Mercurial and Git APIs to the base API.
  - Move caching up to the base level.
    - Store symbolic name and resolved name separately, so we can re-resolve the correct commit from the symbolic name after dirtying caches.
  - Rename `supportsRelativeLocalCommit()` to `supportsCommitRanges()` (old name wasn't very good, and not consistent with new terminology like the `--base` flag).
  - Rename `getRelativeCommit()` and `setRelativeCommit()` to `getBaseCommit()` and `setBaseCommit()`.
  - Introduce `reloadCommitRange()` and call it from `reloadWorkingCopy()`.

I think this fixes the problem in D4049, and provides a general solution for the class of problems we're running into here, with D4096. Specifically:

  - We no longer get dirty caches, as long as you call reloadWorkingCopy() after changing the working copy (or call a method which calls it for you).
  - We no longer get order-of-parsing-things problems, because setBaseCommit() reloads the appropriate caches.
  - We no longer get nasty effects from calling `requireCleanWorkingCopy()` too early.

Test Plan: This is pretty far-reaching and hard to test. Unit tests; ran various arc commands. :/

Reviewers: vrana

Reviewed By: vrana

CC: aran

Differential Revision: https://secure.phabricator.com/D4097
Implement --everything, --json and --ugly flags for `arc unit`

Summary: Adds "arc unit --everything", which runs every available test, provided the test engine supports it. Also add JSON output.

Test Plan: Ran `arc unit --everything` in arcanist/, libphutil/ and phabricator/. Saw all tests run.

Reviewers: btrahan, vrana

Reviewed By: vrana

CC: aran

Maniphest Tasks: T2065

Differential Revision: https://secure.phabricator.com/D4214
Stop passsing bogus 'user' parameter to differential.createrevision

Summary: After D4191 this is a fatal.

Test Plan: Created this revision.

Reviewers: vrana, btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D4219
Allow arc to be run in arcanist/ or libphutil/

Summary:
Currently, if you run `arc` in arcanist/ or libphutil/ and your PATH and on-disk configuration are set up so a different version of arc or libphutil are the ones that actually load, we fail with an exception like "running arcanist in a different copy of arcanist is not supported".

This causes problems for Harbormaster, since we'd like to be able to run 'arc' in a copy of libphutil/ and have it execute unit tests for that copy rather than failing abruptly. So, if we detect that we're in arcanist/ or libphutil/, execute 'arc' again with the same arguments but force it to load the working copy in place of either the 'arcanist/' or the 'libphutil/' that it decided to load.

This is pretty much horrible black magic.

Test Plan: Ran 'arc list --trace' inside copies of libphutil/ and arcanist/ outside of the normal include chain. Saw it detect these, emit a message, and re-execute itself correctly.

Reviewers: btrahan, vrana

Reviewed By: vrana

CC: aran

Maniphest Tasks: T1049

Differential Revision: https://secure.phabricator.com/D4225
Support http basic auth and related configuration

This adds the http basic auth username and password if found in the
configuration to the ConduitClient.

Reviewed by: epriestley
Bugfixed undefined variable $commit.
Merge pull request #62 from bonneval/bugfixUndefinedVariable

Bugfixed undefined variable $commit.
Merge branch 'master' of http://github.com/facebook/arcanist