SDK / exoplayer

Note: This adds support for the majority of DASH live streams,
however we do not yet correctly support live streams that rely
on UtcTimingElements in their manifests.

Issue: #52

Plus start to properly document the SmoothStreaming package.
Note that where the documentation is a little vague, this is
because the original SmoothStreaming documentation is equally
vague!

- Split sample pools for video/audio/misc, since the typical
  required sample sizes are very different (and so it becomes
  inefficient to use a sample sized for video to hold audio).
- Add TODO for further improvements.

Issue: #174

dev -> dev-hls

The timestamp scaling in SegmentBase.getSegmentTimeUs was
overflowing for some streams. Apply a similar trick to that
applied in the SmoothStreaming case to fix it.

- Move all three buffering constants to a single class (the
  chunk source).
- Increase the target buffer to 40s for increased robustness
  against temporary network blips.
- Make values configurable via the chunk source constructor.
- Treat captions as a text track for HLS. This allows them to
  be enabled/disabled through the demo app UI.

Issue: #165

- Add options to switch abruptly at segment boundaries. Third
  parties who guarantee keyframes at the start of segments will
  want this, because it makes switching more efficient and hence
  rebuffering less likely.
- Switch quality faster when performing a splicing switch (when
  we detect that we need to switch variant, we now immediately
  request the same segment as we did last time for the new variant,
  rather than requesting one more segment for the old variant
  before doing this.

playlist type (master or media).

Issue: #155

dev -> dev-hls

Correctly handle redirection when requesting manifests.

dev -> dev-hls

gradle plugin 0.14.4 fixes

fixes broken import statements

1. Correctly replace the AES data source if IV changes.
2. Check the largest timestamp for being equal to MIN_VALUE, and
   handle this case properly.
3. Clean up AES data source a little.

Issue: #162

The actual fix here is to not call discardExtractors in HlsSampleSource
whilst the loading thread that's pushing data into it is still running.
It's required to wait for that thread to have exited before doing this.

Issue: #159

dev -> dev-hls

Issue: #158

Merge dev -> dev-hls

MediaCodecTrackRenderer: Avoid excessive garbage generation

TsExtractor: Account for frame cropping when parsing SPS

Issue: #153

- Unredact internal error ids.
- Move images.