rename AGENT_TYPE_VOXEL and PACKET_HEADER_DOMAIN_RFD
more renaming for AGENT_TYPE_VOXEL_SERVER
remove ShareAudioFactors struct from audio-mixer
unthread DS check in, allow agents to tell DS who they want to hear about
use new non-threaded method to checkin with domain server
agentTypesOfInterest need not be unsigned and remove debugging
ask only for agents of type AGENT_TYPE_VOXEL_SERVER
if an agent doesn't send a list of types of interest assume it wants to hear about nobody
hook audio-mixer up to new domain server check in method
hook the avatar mixer up to the new domain server check in method
hook eve up to new domain server check in method
prepend the agent types of interest with the number that follow
fix bug with sent and received agent interest packets
hook injector up to new domain-server interest list
hook up voxel-server to domain-server interest list
Merge remote-tracking branch 'upstream/master' into conditional-ds
remove hacked method to keep servers alive
Merge pull request #522 from birarda/conditional-ds

allow agents to specify which agent types they want to hear about