Fix for #1435
Created by: dsparacio
Also moved these three events from core to MPE to allow easy access from player using const value. Added jsdocs.
/**
- Triggered when a fragment download has completed.
- @event MediaPlayerEvents#FRAGMENT_LOADING_COMPLETED / this.FRAGMENT_LOADING_COMPLETED = 'fragmentLoadingCompleted'; /*
- Triggered when a fragment download has started.
- @event MediaPlayerEvents#FRAGMENT_LOADING_STARTED / this.FRAGMENT_LOADING_STARTED = 'fragmentLoadingStarted'; /*
- Triggered when a fragment download is abandoned due to detection of slow download base on the ABR abandon rule..
- @event MediaPlayerEvents#FRAGMENT_LOADING_ABANDONED */ this.FRAGMENT_LOADING_ABANDONED = 'fragmentLoadingAbandoned';
Some player level changes as well.