Correct 'DOULA_REGISTERED' analytics event to properly specify DOULA as the event_model.
user_management: Removing unnecessary code from index view function
Adding analytics events to user_directory app.

user_search_results(view): added 'DOULA_PROFILE_CLIENT_PREVIEWED' event

user_profile(view): added 'DOULA_PROFILE_CLIENT_VIEWED' event
user_management(user_registration_form): add form cleaning method that verifies high price is >= low price.
user_management: Updating __unicode__ for Doua Model