SDK / exoplayer

Issue: #214

Previously samples belonging to disabled tracks would just
accumulate in an arbitrarily long queue in TsExtractor. We
need to actively throw samples away from disabled tracks up
to the current playback position, so as to prevent this.

Issue: #174

I'm not sure exactly what the implications of this change are,
but I'd really hope that only one program in each stream is carrying
audio/video. For GoPro cameras, they expose the video stream in
the second program, for some reason.

Issue: #116

We've seen a few streams where this assertion fails. If you
just skip the packet, things appear to recover correctly in
all cases I've seen, so replacing failure with a warning.

dev -> dev-hls

If the server actually gives us a DEFLATE response, we
fail to handle it properly!

AudioTrack will mark 0-size buffers as consumed

This can happen in the first, non-codec-config output buffer
from MediaCodec, while decoding MP3 data.

This issue was discovered on Nexus 5's running both KitKat
Lollippop.

dev -> dev-hls

- Handle read returning NOTHING_READ for AC-3 streams.
- Remove extra checks for the audio track being initialized.
- Call isInitialized() instead of checking audioTrack != null.

This just brings HLS treatment in the demo app in line with
DASH and SmoothStreaming.

dev -> dev-hls

- We can't refer to UnsupportedSchemeException outside of the
V18 compat inner classes.
- There were also a few missing return; calls.

ac3Bitrate is set only after the first buffer is handled, which meant that
getting the playback position would cause a divide by zero before then.

When playing back AC-3 content, the ac3Bitrate will always be set after the
first buffer is handled, so return a 0 position if it is not set.

Also add missing file.

- Adds support for dash manifests that define SegmentTemplate
  but no SegmentTimeline.
- Assumes that the device clock is correct when calculating which
  segments to load. The final step here is to use the Utc timing
  element in the DASH manifest to obtain an accurate client clock.
- Doesn't yet enforce that the client shouldn't load segments that
  are in the future or behind the live window.

This wasn't actually used for anything other than showing a
toast, which is now generated based on the manifest instead.

Issue: #200

dev -> dev-hls

Also update gradle files.

Github issue: #183

dev -> dev-hls