[ios] - add AE_FMT_FLOAT support (commented out as it doesn't give higher performance on atv2 - but want to leave that code in for the future)
[ios] - refactor setupAudio
[ios] - fix the conditional chaos in checkSessionProperties
[ios] - remove rendercallback in deinitialisation for sanity and reorder deinit parts a bit
[ios] - announce dts and ac3 support for atv2 and tvout situations
[ios] - don't deinit internal sink twice - its already done in the d'tor