Adding example for custom event bindings.

hjkl for directions.
space to move to next slide.
esc for 3D overview (instead of space)

Overview mode shows hidden fragments. (closes #30)

change back state event scope, document level makes more sense as that's where the state class is applied

Firing custom event based on data-state name. This allows developers to trigger custom javascript code on a per slide basis.

Added support for wireless presenter

reveal.js was failing when the hash was of an unexpected format

Mouse scroll handling