[#7593] ticket:627 Add ability to add audit entries for users
[#7593] ticket:627 Change input to text area to give more space for comment
[#7593] ticket:627 Tests for adding audit trail entries
[#7593] ticket:636 set by param to required and added g.markdown.convert to the message
[#7593] ticket:636 Remove unused imports
[#7593] use nl2br in audit log rendering

markdown rendering was causing problems with some project audit log lines like:
`updated "post" permission: "*authenticated" => "*authenticated, *anonymous" for tickets`
which contain `*` and was causing italics.  It also was adding some white space
and seemed to make long audit logs take a little longer to render.