Module /data.pm
TODO list:
  1. remove_connection
 Functionality list:
  1. on_DB_activate
  2. rebuild_oDBs
  3. add_connection
  4. load_preferences
  5. save_preferences
  6. load_preferences
  7. set_userhome
  8. get_userhome
  9. all_prefs
  10. prefs