Fix check for River ID exempt users

Need to hash the password before we hand over to hash_password()
Better RiverID handling in user admin

* Solves the majority of ushahidi/Crowdmap#143
* RiverID's are registered as soon as a new user is created
* Admins can no-longer change email addresses since that would mess with
  the river id association.  (w/ riverid enabled)
* Admins can no longer set passwords for users during creation
  (w/ riverid enabled)
Fix some formatting / indenting on profile controlelrs and user model
Make riverid message in registration translatable
Fix RiverID error message getting 'auth.password' added to it

We're using a fake translation of '%s' here then passing the
RiverID message through to Kohana::lang()