* case insensitive name comparisons

* case insensitive name comparisons
* corectly handle RRsets
* make addresses unique
* return to probe state on conflict
* a bunch of fixes detected while testing against the Apple Bonjour Conformance Test
* a fix in avahi_record_lexicographical_cmp() regarding TXT records
* API for choosing alternative host and service names
* remove a bunch of unused crap from cache.c and server.c
* flush cache when an interface becomes unavailable

git-svn-id: file:///home/lennart/svn/public/avahi/trunk@72 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe