#80 Move parsing of login name

[Stefan Becker]

The discussion on Red Hat Bugzilla #1178686 uncovered another old, now obsolete, assumption in SIPE code:

• backends parse login name to pass login domain to core
• core just passes login domain around, but doesn't use it
• sip-sec modules receive domain, but not all of them use it
• sip-sec-gssapi needs to re-assemble the GSSAPI username using login domain and name. In case of gssapi-only setup this isn't needed, because GSSAPI should do the parsing.

Therefore login name parsing should be pushed down to the sip-sec modules:

• backends should not touch login name
• remove login_domain from sipe_core_allocate()
• remove authdomain field from sipe_core_private and others
• remove domain parameter from sip-sec acquire credential interfaces
• implement username parsing in those sip-sec modules that need it: gssapi (when HAVE_GSSAPI_ONLY is not defined), ntlm, sspi

[Stefan Becker]

Implemented by git commit a1b2ed3