Add dealing with newlines for editor to 5.1-to-6.0

backport of https://github.com/gitlabhq/gitlabhq/commit/2d681c0d1ed14bf23c041aa04fa3e77caceda9a1
Add, delete labels via API
Update labels via API
Update gemnasium-gitlab-service
Update org-ruby
Disable label submit button if any field is empty
Move label coffeescript from view to class
Add testcase for invalid color
Labels need to be valid on name
Validate label titel in project scope
Trigger an update of save button if user pressed a preview color
Do label validation for issues/merge requests API
whitespaceses at beginning of commit messages
gfm and preserve commit message

for commits#show
diff unfold
Mention username option for developers in gitlab.yml

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Merge pull request #7281 from skv-headless/diff-unfold

unfold commits
Fix Md style for API.
Merge pull request #7465 from Razer6/better_label_color_validation

Better label color validation, fixes #7454
Change default label color

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>