Use HTML5 appcache rather than CDN

Here's a modification to consider...
I've been playing with using the HTML5 appcache rather than the CDN's for assets and have found (at least on my iPhone5) that opening of the page is noticeably faster on loads after the initial one, probably due to the fast that index.html, main.js, and main.css are also cached locally now.  This method has the added benefit for users that don't like the idea of using CDN's for "privacy" reasons.  I'd be curious to know if my performance observations are inline with other devices, as I only have an iPhone5 & desktop to test with.

I've included a python script updateAppCache.py to build the manifest file up for you when a change an asset or do a version release.  Additonally there is a .htaccess
file to set the proper content-type for the manifest file.