Changes since: SkypeTX 1.8.1.4
NEW - Implement reliable avatar updates
FIX - Ensure start-up of STXC clears SinkAudioVideoIds and SourceAudioVideoIds registry keys
FIX - Remote device (handset) audio not working for a new call
FIX - Change installer to use localized service login for NT AUTHORITY\NETWORK SERVICE
FIX - Change registry creation code to use network service localized
FIX - Errors starting up due to missing DefaultDeviceGuids registry subkey in channel directory
FIX - Raise channel state change event after channels cleared back to 'ready'
FIX - Fix to common library for answering flag on calls
FIX - Audio delay starting
