uac: reset registration authentication flag

- reported by  rene montilva (fs#352)
usrloc: db_update contact by instance + reg-id
registrar: clean static values at pack_ci
modules/mtree: added 'multi' param to mtree definition
- new 'multi' param makes it possible to store both integer and string
  typed mtrees into single db table
tls: include dprint.h where log functions are used
pkg/kamailio/centos: Improvement to the CentOS init.d script
tls: extended supportd tls methods

- TLSv1.1 and TLSv1.2 (from openssl 1.0.1e on) added to the internal
  list
tls: listed TLSv1.1 and TLSv1.2 as values for tls_method parameter
tls: refreshed the README
tls: ifdef to use TLSv1.1 only for openssl/libssl v1.0.0+