Small additions around "togglePause()" 

Hello !

These 2 commits add 2 micro features :
* the ```togglePause()``` method is now "public", in case anyone needs to trigger it from its own JavaScript
* the "191" keyCode triggers this ```togglePause()``` method : this adds compatibility with the Logitech presenter tools "black screen" button (I only own the [R400](http://www.amazon.com/Logitech-910-001354-Wireless-Presenter-R400/dp/B002GHBUTK/ref=sr_1_1?s=electronics&ie=UTF8&qid=1358525203&sr=1-1&keywords=r400+logitech), but I guess that other Logitech similar tools send the same key code)