Upgrade opus from 1.0.2 -> 1.0.3
Upgeade avahi to 0.6.31

Additionally, link compatability files for dns_sd.h and howl as these are
needed to build mumble and potentially other avahi using derivations.
Properly configure mumble to build without the server and libopus
Add Build Script for Murmur
Merge pull request #1321 from wkennington/mumble

Break mumble into client and server components