modules/uac: upgrade doc to module.type.name format
modules/uac: update README
modules/debugger: Added dbg.mod_level RPC command
modules/debugger: refresh README
uac: Added ability to set Call-Id through $uac_req(callid).
modules/sdpops: Added new function sdp_get_line_startswith(avpvar, string).
core: added fields to message structure and branch structure to hold user-agent string retrieved from usrloc
modules/pv: added PVs to provide access to the user-agent string retrieved from usrloc
modules/registrar: store user-agent string retrieved from usrloc in msg and branch structures
modules/tm: copy user-agent string retrieved from usrloc into branches when serial forking
modules/ims_registrar_scscf: use #define from core .h to specify the maximum UA length
modules/{various}: updated because there is now an extra parameter on the append_branch() function
core and modules: make IPv6 default, remove compile time flags

* Make IPv6 the default in the core and affected modules
* it has been default switched on since a long time, and was introduced in 2002
* even on embedded systems one probably want now proper IPv6 support
* there was an issue in cygwin in 2008, but IPv6 is there also available since v1.7
* remove over 160 #ifdefs, cleanup the code a lot and removes many of rarely
  tested alternative code paths to ease support of the codebase
* note for gentoo maintainer: please review your packages, they will maybe not
  work now correctly anymore if somebody specified -ipv6 in the use flags
parser/sdp: Fixed segfault in sdp_print() when no SDP body.

- Failed scenario:
remove_body();
msg_apply_changes();
sdp_print("1");

- Result: sdp=0x0
Merge branch 'master' of ssh://git.sip-router.org/sip-router
modules/outbound: moved the check for "Supported: outbound" to after the checks on the Route: header

- In the scenario when a call comes from a non-outbound end-point to an
  outbound end-point the outbound options-tag will not be present, but outbound
  should still be used on the final leg between the edge-proxy and the
  end-point.
modules/msrp: Updated documentation
modules/outbound: Updated documentation
modules/websocket: Updated documentation
pkg/kamailio/(centos|fedora): refactored .spec