Improve MR building

* fix 500 error when no parent for initial commit
* fix link from diff files to wrong commit

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Only redirect to referrer from public GitLab pages
fix high cpu usage issue that occured in Firefox

fixes issue related with #342 (Merge Request view causes 100% CPU in firefox)

Conflicts:
	CHANGELOG
Add patch release changelog

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

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Merge branch 'patch-release' into '7-1-stable'

Patch release

Part of #1470

See merge request !1000
Merge branch '7-1-stable' into zh

Conflicts:
	app/views/layouts/_public_head_panel.html.haml