Merge remote branch 'origin/tmp/k3.0_sr_backports' into sr_3.0
statistics callback support (enabled only if compiled with
-DUSE_CORE_STATS) and latest kamailio 3.0 fixes
* origin/tmp/k3.0_sr_backports:
core: new param to give outbut buffer size
core: use one buffer for int2str
core: use dlflags to load modules
uac(k): use header types for detection
uac(k): proper test for send failure
uac(k): set type for tm callback
core: stats events cbs are called only if USE_CORE_STATS is defined
update drp_reqs statistics
update drp_rpls statistics
update fwd_rpls statistics
update err_reqs statistics
update err_rpls statistics
update bad_URIs statistics
update bad_msg_hdr statistics
core: update fwd_reqs stat
kex: support to update core stats via core events
core: added new event SREV_CORE_STATS