WIP: gitlab-grit gem to replace grit fork

Implemented grep support

This reverts commit 00a00543.

This reverts commit cdf0fdb3.

This reverts commit b49a6ff4.

Merge branch 'fix_non_ascii_issue_in_diff' of https://github.com/ranmocy/grit into ranmocy-fix_non_ascii_issue_in_diff

Strip GPG signatures

Make sure we don't split on a `ref:path' revision.

update mocha to support tests on ruby 2.0.

Fixes symlinks omission from diff.

support ruby 2.0

otherwise "..."'s encoding is UTF-8 in ruby 2.0.

There's no third argument to Tempfile#open under 1.8.7. The default
mode is w+ which should be fine and there's no encoding support so
the binary flag doesn't matter.

Atomic object writes