Instruct users to fetch merge request branch

Instructing users to create a new branch on the target branch and then
pulling creates a few issues. If the target branch has moved on since
the source branch diverged from it, then the pull will create an
unnecessary merge commit from the target branch to the source branch. If
the user has pull.rebase set to "true" or "preserve", then this creates
an even stranger history. These instructions will ensure the local
branch created for the merge request is exactly what contributing user
has pushed.
Attachment URL with non-/ relative root

The attachment URL was not working with relative_url_root not equal to '/'. I suggest this fix.
append .xmlschema to system hook timestamp
Change gitlab/log permissions in installation.md

This patch changes default permission of the gitlab/log directory to
u+rwX,go-w. This is done to make the directory NOT readable by group and
others and to avoid logrotate complaining about it. chmod 755 is not
used to avoid setting executable bit on file within the log dir.
Adds comments to commits in the API
Fix version of test seed branches.
Update default regex message to match regex.
Add issueable actor
Move new blob commit message textarea below editor

- match edit blob view
- you enter the commit message *after* you make the modifications
Remove unused authenticate_user from project#show

Redundant with the authorize_read_project! filter
update slack-notifier to 1.0.0, use raw webhook_url per slack recommendation

per changes with slack, they’re now using “static” web hook urls that describe the team & service with IDs that don’t change if the team or service name change. their recommendation is to use the raw webhook_url instead of building it out of components to allow more flexibility

this should also prevent issues cropping up with mistakes in how the urls are parsed
Fixed missing end-of-code line in 7.4 upgrade doc
Transform remove blob link into button.
Merge pull request #8162 from jmsche/patch-1

Fixed missing end-of-code line in 7.4 upgrade doc
Create dev fixture projects with fixed visibility
Factor behaviors.scss constants
improve ssh key emails
Drop all Postgres sequences during backup restore
Removed + '' +
Add CHANGELOG entry for sequence drop