Merge branch 'rs-absorb-gitlab_git' into 'master'

Gemfile

Gemfile.lock

app/models/merge_request_diff.rb

lib/gitlab/git/attributes.rb

lib/gitlab/git/blame.rb

lib/gitlab/git/blob.rb

lib/gitlab/git/blob_snippet.rb

lib/gitlab/git/branch.rb

lib/gitlab/git/commit.rb

lib/gitlab/git/commit_stats.rb

lib/gitlab/git/compare.rb

lib/gitlab/git/diff.rb

lib/gitlab/git/diff_collection.rb

lib/gitlab/git/encoding_helper.rb

lib/gitlab/git/path_helper.rb

lib/gitlab/git/popen.rb

lib/gitlab/git/ref.rb

lib/gitlab/git/repository.rb

lib/gitlab/git/tag.rb

lib/gitlab/git/tree.rb