Exposed more internal methods as external APIs

Hi,

I've been using your plugin (it's great, btw!), I've made a few adjustments for my own application which you may or may not be interested in.

Mainly I've been adding public methods (getVideo, getVideoIndex, setVideoIndex, addVideos).
I've updated how the src of a video is parsed. It allows the caller to provide a simple string rather than an array (this was useful for me because I'm generating the json for the video list in Java, and it let me keep that Java class simpler).

I've also added a mapping from .mov to video/mp4