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
Handle undefined text area values

Check to see if a text area's `val` is defined before trying to call
`replace()` on it.
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 dev user seed: multiple ID was used twice.
Fix version of test seed branches.
Use blob local instead of instance.
Use button type=submit instead of input.
Update default regex message to match regex.
Disable / hide MR edit blob button if cannot edit.
Prepare ForkService to support forking projects to given namespaces

Remove overload of BaseService.initialize, so initialize gains params,
which is used to pass the namespace (like e.g. in TransferService).

The namespace is checked for permission to create projects in it.
Remove unused Project#code function.
transfer_service_spec: cleanup, merge common code, check against nil

- replace creation of group2 with the use of group without add_owner(user)
- fold TransferService calls into new test function transfer_project
  - remove currently not used (and not working) gitlab_shell stub
    (will submit testcase simulating failure in gitlab_shell separately)
- add checks against not be_nil (result.should be_false passes even if nil)
Add issueable actor
support latest firefox esr release
Display renamed files in diff views

Show both the old and new filenames when viewing the diff for a renamed
file.
Add tests for tree edit routes

Critical because of possible confusion between /:id/preview
and /:id for a path that ends in preview.
Disallow POST to compare: does not create objects