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
Remove unused title parameter.

It is always overridden by to humanized source branch name by
MergeRequests::BuilService, which is used by new_project_merge_request_path.
Handle undefined text area values

Check to see if a text area's `val` is defined before trying to call
`replace()` on it.
add sign-in count

add sign-in count to admin section profile view
add HSTS Policy warning

Add warning about HSTS header as it means user will need to provide secure connection access to site for next 24 months from page view. See https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security for more details.
Source repo is now clickable.
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.
Factor issue and edit MR form label field and submit.
Remove test line without effect because no should.
Factor out Emoji parsing using html-pipeline-gitlab
Adds comments to commits in the API
Fix milestone link in issue. Closes #174 (gitlab.com).
Make hyperlinks out of the links.
Add option to gitlab config to specify if LDAP server is active directory.
Fix attachment upload link bug caused by introduction of zen mode.
Simplify custom MR good commit message hint.
Improve new file commit placeholder.
Improve remove file textarea placeholder.