Cleaned up su_addrinfo.c.
Cleaned up su_addrinfo.c.

Cleaned up comments.
Using SU_HAVE_ flags.
Added support for SCTP in getaddrinfo() replacement.

darcs-hash:20051130222604-65a35-0a712c9e4f57a9582c4b3f08879cca9e83220966.gz

unispeech/sofia-sip,erdincay/sofia-sip,BelledonneCommunications/sofia-sip,BelledonneCommunications/sofia-sip,jart/sofia-sip,xhook/sofia-sip,BelledonneCommunications/sofia-sip,erdincay/sofia-sip,unispeech/sofia-sip,jart/sofia-sip,erdincay/sofia-sip,xhook/sofia-sip,unispeech/sofia-sip,xhook/sofia-sip,unispeech/sofia-sip,xhook/sofia-sip,jart/sofia-sip,BelledonneCommunications/sofia-sip,erdincay/sofia-sip,xhook/sofia-sip