More attempts to reduce underrun audio glitches with multichannl and high samplerate
Support planar formats

Mostly just plumbing as planar/float is now handled by GPU.
Requires recent firmware.
Avoid hang following jpegs that failed to decode

There's a few instanced of xbmc hanging following a jpeg that failed to decode on GPU:
http://forum.stmlabs.com/showthread.php?tid=14839
https://github.com/raspberrypi/firmware/issues/288
http://openelec.tv/forum/120-news-announcements/70709-openelec-4-0-released?start=15#105219

It should fail and continue with software decode. It hangs on the OMX_FreeBuffer call.
Looks like image_decode component should be returned to idle state before freeing buffers
when operation did not complete successfully
Restrict the number of outstanding jpeg calls to gpu

Allowing more than one outstanding call to gpu for texture encode/decode can be beneficial as processing
can be overlapped with vchiq message transfer.

Experimentally, 3 outstanding operations is optimal.

Allowing more that this ties up memory on GPU without any performance benefit, so avoid submitting more jobs
Explictly choose deinterlace method for 1080i

As the 1080i deinterlace doesn't require the 3 frames of context we can save ~9MB by requesting it explicitly
Reduce GPU memory use when limited

Switching from default triple buffered output to double buffered saves 8M with 1080p GUI.
This may slightly reduce framerate, but is likely to be minimal.

Assume if gpu_mem is set below the default 128M that this memory reduction is wanted
Make gui limit default to 720 when memory is limited

On a 256M Pi, it's safest to default to 720p gui as memory is quite limited.
videoplayer: adapt lateness detection and dropping to buffering
video player: present correct pts to user for a/v sync (after buffering in renderer)
[omxcodec] Switch to MMAL decoder with MMAL renderer
[omxplayer] Allow choice of omxplayer through acceleration settings
[omxcodec] Enable omxcodec for Pi