UI improvements

* lighter color for comments count
* better UI for issue assigee.milestone block

See merge request !1551

* lighter color for comments count
* better UI for issue assigee.milestone block

Ui improvements

* improve UI for commits, issues and merge requests lists
* refactor commit css

See merge request !1550

Ui improvements

* update bootstrap
* move milestones and labels to the left
* make open/closed/all filter as tab
* make issues page more compact

For  #1871

See merge request !1549

Correctly set default projects limit for new users.

See #2014.

Note that the projects limit still isn't retroactively applied to existing users (probably as intended)

See merge request !1547

Add missing color codes for line anchors, fixes #8628

Document fun facts about omnibus-gitlab

I hope this helps developers understand some of the differences.

See merge request !1546

Revert upload refactor

See merge request !1548

This reverts commit 7d5f86f6.

This reverts commit ebd39fc0.

Update API branches documentation [ci skip]