Summary:
Ref T3186. We have about 50 linters which run programs and read the results, all of which have ad-hoc one-off custom config that isn't formalized anywhere.
Consolidate all this stuff into `ArcanistExternalLinter`, which is configurable through `.arclint` (although nothing supports this quite yet).
Extend CSSLint and Pep8Lint from `ArcanistExternalLinter`.
Add unit tests for both.
There are still some rough edges here, but it mostly seems to work pretty well.
Test Plan: Ran unit tests, hit some (most?) of the error cases.
Reviewers: btrahan
Reviewed By: btrahan
CC: chad, aran, Firehed
Maniphest Tasks: T3186
Differential Revision: https://secure.phabricator.com/D6800
