Enable canvas resize support and add mobile device support

I've used @iirelu [changes](https://github.com/maroslaw/rainyday.js/pull/28) to allow for canvas resize events as well as adding support for mobile devices. By changing  
'window.innerWidth, window.innerHeight' to 'document.body.clientWidth, document.body.clientHeight' we're able to correctly find out the height and width of a mobile device (including the scroll height) so it works on iOS devices.