New headers and parameters from RFC 3455 and UUI drafts

These changes derive from mail by John Gregg (see http://list.resiprocate.org/archive/resiprocate-devel/msg08665.html). I added additional header to exchange User-to-User information via SIP.
I have the same doubt. I left the sources as modified by my version of gperf, but I agree that it could be better to leave "-k *" option that is present in mainline.
Same consideration is valid for MethodHash.cxx, ParameterHash.cxx  and gperf_w32.bat.