Allow configuration to receive click events, touch events, or both

[cleercode]

Ex: I want a component to only be draggable on touch devices

[mzabriskie]

@cleercode I have a couple PRs for touch events (#9, #18). Still haven't decided which direction to take it, but touch will be the focus of the next release.

[mzabriskie]

This has been resolved with #18.