Remove Deprecated invite / login / identity code

(Bug, To be Fixed , Priority: Critical, Test Status: No automated tests yet , Reported By Justin du Coeur, )
Internals, Invites
Summary: The invitation system has massively changed. After a brief deprecation cycle, remove the dead code.
There is code marked as Deprecated in:
  • PersonModule
  • LoginController
  • handleInvite.scala.html (entire file)
  • joinSpace.scala.html (entire file)
Make sure that invite/join still works after removing this code!