libstagefright: Handle unsupported codec metaData

Modification done in StagefrightMetadataRetriver
to handle NULL return for meta data if codec is
unsupported by extractor.

Change-Id: I905cec5ee91b098d99e1935437b562d2d9206381

Conflicts:
	media/libstagefright/StagefrightMetadataRetriever.cpp
libstagefright: Adds some parsing capability

o Adds AC3, EAC3 and DTS mime types
o Adds AC3/EAC3 support in MP4 parser
o Adds MPEG4 video, MPEG Audio, AC3, DTS, EAC3 support
in mkv extractor.

Change-Id: I9895c0e40e5ad38976004a9569200f1340d525de

Conflicts:
	media/libstagefright/MPEG4Extractor.cpp
AwesomePlayer: Handle unsupported tracks

Change-Id: I0d359e704200d86be237211dc816464f7186080b

Conflicts:
	media/libstagefright/AwesomePlayer.cpp
AwesomePlayer: Handle seek for non-seekable streams

Change-Id: Id07ea9353c2acf72142fdc1890ed434e9ad319a4

Conflicts:
	media/libstagefright/AwesomePlayer.cpp
AwesomePlayer: Fallback to software codecs for video playback

In case HW codec fails to play a video stream, allow fallback to
SW codec.

Change-Id: I9c252a70cd4a4fbb8ab13a7b77419ebaea1d7684

Conflicts:
	media/libstagefright/AwesomePlayer.cpp
Smooth out AwesomePlayer

Use clock estimator to smooth out audio time stamps.

Change-Id: Iec1ff30c011069d06ff8051fc4839d00895463d6

Conflicts:
	media/libstagefright/AwesomePlayer.cpp
stagefright: add ClockEstimator API and WindowedLinearFitEstimator

Change-Id: I74474c385848a8eab2ac0da7c069510378e2b217