Merge changes Icd6d4fc4,Idff221fc,I99f0f79a,Ic310f937,I74879023, ...
* changes:
stagefright: rework MediaCodecSource
stagefright/rtsp: Remove dependence on OMXSource
cmds/stagefright: use MediaCodec* instead of OMXCodec
stagefright: add SimpleDecodingSource
stagefright/foundation: add Mutexed syntactic sugar
stagefright: add PREFER_SOFTWARE_CODEC flag to MediaCodecSource
stagefright: move MetadataRetriever off of OMXCodec
stagefright: change signature of MediaCodec::Create methods
stagefright: create findCodec methods in MediaCodecList
stagefright: move getOMXChannelMapping to ACodec
stagefright: Remove unused ClockEstimator and TimeSource
stagefright: Remove unused TimedTextDriver and Sources