[DRAFT] (do not merge) html5-storage support

Hi,

I've initially begun some work on a PR to support html5 storage in teaspoon. I wanted to get some advice or suggestions as I move forward and make sure it's all kosher with you. I want to have a config variable to enable <code>html5Storage</code> which if set to true, will enable html5storage by injecting an IndexedDB shim. I'm basing this off of code from this issue in phantomJS: https://github.com/ariya/phantomjs/issues/10992#issuecomment-29641607

One snag I'm running into is being able to run <code>asyncTest</code>. Every time I try and use QUnit's async test (even with start and stop) it hangs when I run <code>rake teaspoon suite=qunit</code>. Thoughts? I need to resolve this or else I won't be able to test the async transactions.