NEW - Provide SIP VOIP Extensions for use with USB headsets
NEW - Add ability to match SIP requests on To Header or Request Header
NEW - Add SIP Livewire music on hold
NEW - Allow SDP pass through when receiving calls from SIP provider
FIX - Allow SIP handset port to be specified
FIX - Check ACK from SIP Invite for new audio port
FIX - Improve efficiency of unparking to handset
FIX - Improve efficiency of answering to handset
FIX - Use IP and Port when transferring between handsets
