Milestone Avahi 0.6.19

This is a bugfix release, but also adds a new component "avahi-ui-sharp".

• Rename zssh/zvnc to bssh/bvnc to avoid a name collision with another free software tool, on request of the Debian developers. I hope this name change early in the life of bssh/bvnc won't be too difficult to handle by the distributors.
• Add man page for bssh/bvnc
• avahi-ui: fix segfault when browsing in empty domains
• avahi-ui: allow GTK_RESPONSE_OK, _YES and _APPLY besides _ACCEPT as positive dialog response codes
• avahi-ui-sharp: Add Mono/C# API wrapper for avahi-ui
• Don't pick the first and the last 256 IP addresses from the IPV4LL range in avahi-autoipd, as required by RC3927 section 2.1
• No longer publish the Avahi service identification cookie anymore by default. It was a bad idea in the first place. A better replacement will hopefully be made available in Avahi eventually.
• Properly set umask before writing to /var/lib/avahi-autoipd
• Update .deskop files to work around KDE menu issue
• Various build fixes and other minor fixes and updates

This release is backwards compatible with Avahi 0.6.x with x < 19.