Add support for Blob, ArrayBuffer, Uint8Array

These commits add :
* support for Blob, ArrayBuffer, Uint8Array (when applicable) for loading, updating and generating zip files
* deprecate ```generate({base64:true})``` for ```generate({type:"base64"})```
* add examples of how to use these additions

I tested it in :
* IE 6/7/8/9
* Firefox 3/3.6/4/10(esr)/17(esr)
* Chrome latest
* Safari 5.1/6

This should resolve the issues #23 and #27