Annotations Work

A first pass at annotations integration has been completed with the Aeneas format

Annotations Example

Four new config options for playlist have been added

// Array of annotations in [Aeneas](https://github.com/readbeyond/aeneas) JSON format
annotations: [],

// Whether to automatically scroll the waveform while playing
isAutomaticScroll: false,

// If false when clicking an annotation id segment
// playback will stop after segment completion.
isContinuousPlay: false,

// If true annotation endpoints will remain linked when dragged
// if they were the same value before dragging started.
linkEndpoints: false,

In correspondence, four new events have been added to invoke.

event	arguments	description
automaticscroll	true/false	Change property isAutomaticScroll.
continuousplay	true/false	Change property isContinuousPlay.
linkendpoints	true/false	Change property linkEndpoints.
annotationsrequest	none	Requests to download the annotations to a json file.