Merge pull request #111 from SolidStateGroup/milestone-4-5

Milestone 4 5
Card #213 use BaseUser for conversation recipients, fix create conversation (much smaller POST)
Card #213 diagnostics, enter results, results detail given title 'Results' so menu is shown as selected
Card #226 set error page public (no auth needed)
Card #186 patient messaging security, more sensible user information object in front end
/api/error prints exception message
auth testfix
more verbose authentication error log
temporarily disable redirect to error on auth fail, print entire request header to log
enable redirect to error on auth fail, print entire request header to log,
path contains rather than startswith for public paths
more logging
corrected public urls
corrected public urls
removed logging on every request
Card #242 unit admins cannot change their groups from unit to disease group (or anything else)
Card #242 non global admin users cannot start conversation with themselves
Card #242 updated help, note: do we need to show help link on front page when not logged in?
Card #242 staff and patient specific help
Card #213 nicer login fail message
Card #213 hide join request button from unit staff