Customise video with options

#148 Introduces options to influence track selection on the ExoPlayer.

Only emit onBeat when player is playing

#141 Updates the version of exo-player

#142 Only emit an onBeat when player.isPlaying. As an example, a client could perform player.play followed by player.stop but between the play and stop being triggered a beat is scheduled to occur. The stop doesn't occur before the event is emitted so the client is notified of the beat, if the client then tries to access some methods on the no-player they will receive a crash, even though they are notified with a valid instance of the player.

Add support for volume/mute

#139 Add API to change volume

Add support for Webvtt subtitles color

#136 updates the ExoPlayer dependency version to 2.7.1
#137 adds support for subtitles colors defined in Webvtt cue Class tags

Fix subtitles position

#133 fixes a bug where we were ignoring the cue attributes line and align

Polish error handling

• Map exoplayer errors by looking at the thrown ExoPlaybackException type before unwrapping real exception.
• Include new error types for better granularity and remove deprecated ones.
• Honour documentation by not prematurely invoking Player.EventListener.onPlayerError() for errors where the documentation says to do not so.

Reduced volume bug fix

#129 Low volume fix - Setting exoplayer audio attributes
#130 Dependencies update

Alleviate Memory Churn

This release tries to deal with some of the memory churn associated with the creation of VideoPosition and VideoDuration by using primitives over complex objects. See #106 #107 for more information.

Updates to v2.6.0 of exo-player see #115 for more information.

Clear track selections

Cancels previous calls to NoPlayer.select[Video/Audio]Track leaving the track selection to the internal ExoPlayer instance. Not currently implemented on MediaPlayer. See #102 for more information.

Video track selection

Introduces video track selection so that clients can select a rendition quality dynamically during stream playback. See #99 for more information.