[omxplayer] Allow small audio packets to be concatenated to make better use of audio fifo

Some audio codecs produce small packets which causes a high overhead when submitting to GPU, and doesn't make full use of GPU side buffering.
TrueHD in particular can produce packets with 40 samples (so 1200 packets per second) which causes very high overhead.

What this aims to do is to concatenate audio packets until they approach the ideal audio packet size,
and then deal with the awkardness of concatenated planar formats.
[EGL] Initialise resolution to current window size
[omx] Skip the resize when not needed when decoding jpegs

The decode to texture path almost always uses cached jpegs that are the correct size, so the resize is rarely needed.
The re-enc path usually needs resizing, but may not where the source is small.

Skipping the resize stage saves a little time and memory on GPU and also saves some setup time.
[omxplayer] Skip picture attachments in music files they cause audio to hang
[omxplayer] Use media for determing audio delay and cache time

I've also added caching to the call to OMXMediaTime as the GPU round trip is expensive when called too frequently
- before doing the real airplay service zeroconf announcement announce the same thing with different friendlyname - odd try to fix ios7 clients
[omxplayer] When setting fullscreen flag we don't want noaspect

We set the fullscreen on 3d videos to avoid scaling breaking the 3d affect.
However we also set the noaspect flag which means widescreen videos (e.g. 1920x800) will get stretched vertically which is unwanted.
[hifiberry] Hack: force it to be recognised as IEC958 capable to enable passthrough options
[PiSink] Fix some issues with buffering and multichannel

Also support AE_FMT_FLOAT and AE_FMT_S32 (requires updated firmware)
Buffer is increased to 100ms to reduce chance of underrun.