Features & Fixes

c_sync: Add methods for camera to world and resolution (@martyvona, @mcteo). #294 #301
Use audio serial for models that do not provide a valid camera serial (@olzhas). #360 #393
Audio support is no longer conditionally compiled. #372
Fix micview compile error (@nneonneo). #399
Fix OpenNI2-FreenectDriver crash on exit (@nneonneo). #400

Notes

Each device that used to provide "0000000000000000" as its camera_serial now provides a valid serial from its audio device instead. This does not affect devices that already provide a valid camera_serial. It does not break code that handles "0000000000000000" devices as a special case, but it may break code that uses that serial to identify K4W.
Audio support is now present in all builds and the BUILD_AUDIO flag is gone. Audio firmware is still required for it to work and may be downloaded with fwfetcher.py. The build process will automatically download the firmware when the BUILD_REDIST_PACKAGE=OFF flag is supplied. Note that the firmware may not be legal to redistribute!