have the audio mixer output a stacktrace when it crashes
Merge pull request #213 from birarda/stacktraces

output stack trace on audio mixer crash
include cstdlib for call to exit
Merge pull request #214 from birarda/master

add missing cstdlib include
include signal for signal handler in audio mixer
Merge pull request #215 from birarda/master

another missing include for stacktraces
working on detection of avatars entering into each other's peripersonal space
Merge remote-tracking branch 'upstream/master'