updated fork feature to use gitlab-shell for v5 of gitlab

fix http push 401 and 500 with some git clients

See https://github.com/gitlabhq/gitlabhq/pull/3597#discussion-diff-4014638

When asking to fork a project and a project with the same name
already exists (likely from a previous fork), the recovery from
the fork failure would inadvertantly delete the repo of the
existing destination project.

Assignees are now sorted alphabetically.

[BUGFIX] User suggest at team_members/new not working with relative_url_root

Swapped out placeholder text on teams admin page

Changed "simple Teams description" placeholder subtitle to "allow you
to organize groups of people that have a common focus. Use teams to
simplify the process of assigning roles to groups of people."

Show emoji popup if colon preceding by space or is new line.

Add monokai highlighting theme

Authenticate LDAP users in the grack module - fixed problems - tested code

Diff with better colors and some spacing on the corners

fixed broken gitlab version determination during backup

Upgrade guide cleanup

move the update guides from the wiki into the repo

move the update instructions for 4.2 to 5.0 from the Wiki into the Repo