Make retrieving parents for mercurial commits work consistently across platforms

Summary:
Currently the template is single quoted, but Windows only supports double quotes. This meant that the output would be like:
  lang=text
  'aabbccddeeffaabbccddeeffaabbccddeeff0123
  '

Which is clearly wrong.

This is displayed like that in Phabricator as well, which is confusing.

Test Plan: ran `arc diff` on a Windows machine and saw the correct behaviour.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9450
Apply various linter fixes.

Summary: Applied various linter fixes. Also make the `.editorconfig` file a bit more specific. Unfortunately, `arc lint --apply-patches` currently modifies some test data that it shouldn't, but this should be fixed after T5105.

Test Plan: Ran `arc unit` to make sure things weren't broken.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin, aurelijus

Differential Revision: https://secure.phabricator.com/D9440
Don't lint symlinks by default.

Summary: Fixes T5300. Currently, if a dead symbolic link is linted, all kinds of errors will be thrown by most linters because they will try to read the (non-existent) file contents. Instead, let's not lint symbolic links by default. In the case that the target of a symbolic link is inside the working copy, then it should be being linted anyway.

Test Plan: Created a symbolic link and verified that it wasn't linted (by any linter other than the `ArcanistFilenameLinter`).

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Maniphest Tasks: T5300

Differential Revision: https://secure.phabricator.com/D9448
[LATER] Remove deprecated `mark-committed` workflow.

Summary: This workflow has been deprecated for a long time now. At some stage, it should be removed.

Test Plan: N/A

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9463
Present case of class and interface names.

Summary: Currently, class and interface names are converted to lowercase when comparing minimum and maximum versions. This is necessary in order to compare with the data from `php_compat_info.json` but causes the lint message to be slightly misleading.

Test Plan:
Linted a test file.

**Before**
```
   Error  (XHP31) Use Of PHP 5.3 Features
    This codebase targets PHP 5.2.3, but `iterator` was not introduced until
    PHP 5.3.0.

               1 <?php
               2
    >>>        3 final class FooBar implements Iterator {}
```

**After**
```
   Error  (XHP31) Use Of PHP 5.3 Features
    This codebase targets PHP 5.2.3, but `Iterator` was not introduced until
    PHP 5.3.0.

               1 <?php
               2
    >>>        3 final class FooBar implements Iterator {}
```

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9471
Remove the `ArcanistBaseWorkflow::getUserGUID` function.

Summary: This function has been deprecated for a long time (see rARC8150fdf044818c503a588c1b3ef0ddbb93cfa1be). It should be safe to remove it now.

Test Plan: N/A

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9465
--range support for git

Summary:
This adds support for passing range of commits for arc diff. This is useful when you want to submit code reviews for past commits without mucking around with the working copy.

This will probably require changes :)

Test Plan: Tested locally, but totally need to add tests for this

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9369
Tweak error and status messages for commit ranges

Summary: Improve/clarify some error messages a bit, hopefully.

Test Plan: Ran `arc which`, `arc diff`, etc., with various explicit, implicit, and `--head` flags. Read error messages, didn't catch anything too awkward.

Reviewers: talshiri

Reviewed By: talshiri

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D9489
Merge branch 'master' of github.com:facebook/arcanist