fix checkout tag name
Fix bug in ace-src-noconflict with Relative url.

If we doesn't use a relative url we have this:
<pre>gon.relative_url_root=""</pre>
Else <pre>gon.relative_url_root="/gitlab"</pre>

Gitlab::Application.config.assets.prefix contains:
<pre>/assets</pre>
Merge pull request #4824 from lurdan/patch-1

fix checkout tag name
Render not found when failing to look for a commit
Warn about update to 6.1
Drop deprecated tables
Remove deprecated models
Merge branch 'master' of github.com:gitlabhq/gitlabhq
Add iids to milestones. Moved iids logic to separate concern
Look for milestone by iid in milestone controller
Remove can_create_team code from user
Fix accidentally removed class name
Reannotate
Add z-index to flash message
A little improvement

1. Replace params key 'q' with 'extended_sha1'. A extended SHA1 syntax is explained in 'man gitrevisions'.
2. Change the placeholder of looking for commit.
3. Change the label of ref filter.
Merge pull request #4829 from hiroponz/render-not-found-when-failing-to-look-for-commit

Render not found when failing to look for commit
Merge pull request #4826 from amouhzi/patch-1

Fix bug in ace-src-noconflict with Relative url.
Fix tests after can_create_team was removed
fix conflicts