SDK / exoplayer

Issue: #863

Issue: #874

Issue: #893

Add API to get the version of underlying libvpx and libopus
decoders. Also update the demo app to show the version in the UI.

FLV (H.264 + AAC) support

The sample data position is the sum of the data offset and the base data offset.
The base data offset is either specified in the stream, or defaults to the first
byte position in the moof box. (We only support one traf per moof currently, so
the offset does not need to be assigned for later track fragments.) The data
position can optionally be offset by a data position read from the trun.

The auxiliary information offset is calculated in the same way, but using an
offset read from the saio box.

Issue: #837
Issue: #861

- Added TtmlColorParser to workaround JellyBean issues with named colors.
- Support rgb and rgba expressions as well.

Context:
- Currently, playback is significantly more juddery with it disabled,
  particularly on AndroidTV.
- We should be able to do the "best" job of this internally, so injection
  doesn't buy anything useful. If someone has a better implementation for
  adjusting the frame release, they should improve the core library.

The only Samsung devices with names starting "d2" that we're aware of
are Galaxy S3 variants, and also one Samsung Galaxy Pocket Neo d2aio
SAMSUNG-SGH-I747Z. This change speculatively includes that device too because
its name is very similar to SAMSUNG-SGH-I747 which is known to be affected.

Issue: #548

Issue #838

Documentation: https://developer.sony.com/develop/tvs/android-tv/design-guide/

On API 23 we should also check Display.Mode (where supported).

Issue: #800

Issue: #800

NVIDIA Shield before API 23 supports DTS passthrough, so this change inlines the
constant value.

Try re-sync'ing to the next level 1 element when invalid data is found. This
corrects the behavior for test case 4 in the mkv test suite.

Partially Fixes Issue #631

This makes it possible to exit the player when using e.g. an Android TV with a
keyboard.