SDK / exoplayer

- Have extractors read from an ExtractorInput. Benefits of this are
  (a) The ability to do a "full" read or skip of a specified number
  of bytes, (b) The ability to do multiple reads in your extractor's
  read method. The ExtractorInput will throw an InterruptedException
  if the read has been canceled.

- Provides the extractor with the ability to query the absolute
  position of the data being read in the stream. This is needed for
  things like parsing a segment index in fragmented mp4, where the
  position of the end of the box in the stream is required because
  the index offsets are all specified relative to that position.

- Move to builder naming.
- Propagate formats to the TrackOutput instances, rather than having
  them be read through the Extractor. There was actually some weird
  indexing going on here before (which happened to work, but wasn't
  well defined).

Fix AES decryption of HLS streams.

As per http://tools.ietf.org/html/draft-pantos-http-live-streaming-04#section-5.2,
the initializaton vector (IV) of the AES decryption algorithm should be set to:
- the IV attribute value if present,
- the sequence number otherwise.

Currently, the IV is set once and use over all next media sequences
where the IV attribute is not set. The fix is to use the provided IV if
given or use the current media sequence number.

- It's probably easiest to think of this as a standalone HLS change, which is splitting out the "loading" and "consuming" sides of HlsExtractor and a good structural change in its own right. To do this, HlsExtractorWrapper becomes a final class implementing the consuming side. HlsExtractor becomes an interface defining the loading side.

- The bigger picture is that, hopefully, HlsExtractor will become a lightweight extractor interface that can be used throughout the library. Because it doesn't need to implement the consuming side, we'll save on having to re-implement the consuming side for every extractor (we'll probably need one consuming side implementation for HLS/DASH/SmoothStreaming, and a second one for everything else, both of which will use SampleQueue). It's expected that the HlsExtractor interface will need to change to accommodate all use cases.

- The next step in unification will be to try and have FragmentedMp4Extractor implement HlsExtractor (which will need renaming). Once this is done, I'll try and move the chunk package over to use the HlsExtractor interface.

- This is a step toward hopefully converging HLS and CHUNK packages.
- Add support for encrypted samples.
- Add support for appending from a DataSource.

- The fmp4 extractor was reading from sampleEncryptionData even
  for not-encrypted samples, which I'm pretty sure isn't right.
  Fixed this. For all encrypted content I've seen, this change
  will be a no-op because isEncrypted is always true if there's
  an encryptionBox present.
- Made webm extractor only set cryptoInfo if isEncrypted is true.
- Align variable naming in the two extractors, for clarity.

- Rather than returning a map, return a DrmInitData object,
  with mapped and non-mapped implementations.
- Include a suitable mimeType to pass to the MediaDrm. Previously
  we were incorrectly passing the mimeType of the samples,
  where-as MediaDrm expects the container mimeType. Note that
  it doesn't matter whether the mimeType starts with "video" or
  "audio", hence using video mimeTypes everywhere.

Not yet used by anything.

Issue: #151

- Correctly handle bandwidth NO_ESTIMATE case.
- Don't consider switching without a previous chunk.

Set the duration on the MediaFormat instead.

Issue: #327

It was possible for a codec input buffer to be filled with two frames' worth of
data, if seekTo was called after populating a buffer, if waitingForKeys was true
and seeking did not trigger a flush. This caused the CryptoInfo to be configured
as if the input buffer contained a large amount of reconfiguration data as
cleartext.

Move resetting waitingForKeys to flushCodec, so that we don't try to read the
next sample from the source until the first one has been consumed or discarded.

Also remove uriIsFullStream. It's not doing anything particularly
useful, so I think it makes sense to remove it from the public API;
it's unlikely anyone is using it.

Issue: #329

It seems fairly safe to assume a playlist wont be blacklisted
within 1ms of the device booting :).

Add support for GEOB and PRIV ID3 frames.

Mime type string always finish with a single 0 byte

- Fixed issue in the calculation of size of objectData
- Indentation fixes

Removed the unused method indexOfNot

Modified parse method to take into account different lengths for the
termination character (1 for UTF-8 and ISO-8859-1; 2 for UTF-16 and
UTF-16BE).

For fields encoded using UTF-16 or UTF-16BE charsets when looking for
termination character we have to look for two zero consecutive bytes.

Otherwise, as many characters encoded with UTF-16 or UTF-16BE has one
of their 2 bytes set with the value zero, we will be truncating text
fields.

- Added support for ID3 frames of types GEOB and PRIV.

 - GEOB type is commonly used by dynamic ads provider to include in the
stream information about the ads to be played.
 - PRIV type is commonly used for time synchronization (example:
synchronizing playback of a live stream and its webvtt captions) and
also by analytics companies to include tracking information in the
stream.

- Added a sample stream from Apple that contains ID3 metadata.

Better management of blacklisted playlists

Note: I'm fairly confident that NetworkLoadable.Parser implementations
can live without the inputEncoding being specified. But not completely
100%...

Issue: #311
Issue: #56

The return value here assumed that the time being searched for
was beyond the start time of the last segment. This fix also
handles the case where the time is prior to the start of the
first segment.

The only downside of this change is that MediaPresentationDescriptionParser
is no longer stateless.