Re: [sr-dev] [kamailio/kamailio] ims_usrloc_pcscf: implementation of db_mode DB_ONLY (value 3) (PR #3279)

I finally did a rebase to resolve the conflict in the admin xml. To summarize my changes after first review: 1. removed unnecessary comments 2. changed INFO/CRIT logs into DBG/ERR logs 3. removed my changes to db_insert_pcontact and db_update_pcontact 4. removed method which deleted pua entry in pua db 5. changed definition of cpb_qos and cpb_registrar to declaration in usrloc.h and moved definition to usrloc.c 6. changed the new db queries to the correct generic approach 7. documented 2 new modparams 8. Free cpb_qos and cpb_registrar in destroy method