Full test suite now passes in all browsers! There are probably some tweaks we can...

Full test suite now passes in all browsers! There are probably some tweaks we can make to shorten and simplify.

- removeAttr now only uses setAttribute if camelCase setAttribute is not supported

  + Might want to rename jQuery.support.getSetAttribute

- tabIndex is a special case now for hooks where undefined should be returned.

  + Should we be checking if hooks returns undefined?  undefined might be the desired return value in future hooks.
    As of now, tabIndex is the only one that needs it, but the test suite will still pass if we don't check if hooks are undefined.