Update to 0.8.4:

0.8.4 ("H264")

Another stable release.
- support H264, so all Youtube videos play again
- fix various portability issues for ARM
- fix rare crash with gotoAndPlay() function
- fix rare crasher with setTarget() function
- fix crashes in BitmapData.copyPixels()
- zero memory before rendering in PulseAudio backend
- improve Cairo check in testsuite

(wiz)