Updated the shim to work in Safari with indexes

I had to update the way that indexes were used with cursors. I tested it
in Safari. I basically just got it to work in my use cases, so I don't
know if this will work generically. Probably needs to have some test
cases created and review it more.
Moved the use strict statements into the functions.

This got me around the error I was getting in IE and FF when trying to
set window.indexedDB.
Tried to update the amount of space allocated.

Updated to 4 GB. Not sure if this really works though.