Add support for devices with both touch and mouse input.
Revert "Bind to both touchstart and click.  Closes #4."

This reverts commit 68a75d50e9ebf43f00406f2a379807f48ef4290c.

Conflicts:
	drop.js
	drop.min.js
Merge remote-tracking branch 'origin/pr/4'

Conflicts:
	drop.js
	drop.min.js
Fix event handling