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

Instructions update: install postfix separately, new privilege to mysql users, sockets dir. Fixes #3639

Fixed typo in app/views/deploy_keys/index.html.haml