1. Support Zepto from now on
2. Fix "done" callback
Merge branch 'zepto'
Merge branch 'master' of https://github.com/pakcheong/jqthumb

Conflicts:
	Gruntfile.js
	README.md
	bower.json
	demo/jqthumb.js
	dist/jqthumb.js
	dist/jqthumb.min.js
	package.json