stagefright: More high-resolution audio support

 * Clean up the "error driven" fallback code we had before and
   reconfigure components if the output bit width needs to change
   (a2dp/usb fallback).
 * Decode various formats (AC3/DTS/EAC3) which output floating point
   samples using FFMPEG, which will output 24-bit PCM for us.

Change-Id: I94f5fa59f5f737be8969df4c5ad4295c45cb8657
stagefright: Resolve turf war between FFMPEG and mm-parser

 * There is overlap between the supported codecs, and the extractors
   generally do the right thing. The current code will blindly call
   into the FFMPEG specific functions when some QC codec should
   be used though, so add checks on the component name first.
 * This resolves hitting asserts when using hardware WMA/WMV codecs.
 * Also add a contraint to block the VC1 codec from try to play ancient
   WMV formats, as it will fail.

Change-Id: I3b8aafaef7ae7c0f2e058f78b043380f04a41e73