* Clean up ref name rules
Clean up checks on reference names to better conform to the guideline
here: https://git-scm.com/docs/git-check-ref-format
This fixes half of #6321
* Update branch create integration test
According to: https://git-scm.com/docs/git-check-ref-format
And: git check-ref-format "master/feature=test1"
This is a valid branch name and we should not be testing for it to fail.
* Make URL scheme unambiguous
Redirect old routes to new routes
* Fix redirects to new URL scheme, and update template
* Fix branches/_new endpoints, and update integration test
* Create new branch from branch selection dropdown and rewrite it to VueJS
* Make updateLocalCopyToCommit as not exported
* Move branch name validation to model
* Fix possible race condition
