Adding Keyboard commands to the presentation tool

See #41
Adds the following keyboard shortcuts to presentation tool:

* Next Slide: up, right, enter space
* Previous Slide: left, down, backspace
* Activate Camera: C
* Show Thumbs: T (this could become a toggle instead of show)

As you'll see in the diff, there was some whitespace removed, nothing to worry.
Moved the code that closes video closer to the other event bindings so in a future refactor it will be easier to find all the event bindings on the tool document.
The code for these shortcuts follow the code that is found on ppw.js.