IE 9+ fixes

* Fix making PUT/DELETE requests by uppercasing the HTTP method name
* This also fixes PATCH for Chrome/Safari
* Fix requests with undefined body on IE
* IE 9 fix for connection error
* Fix CSS being applied to test suite

The only test that now fails is the FormData test on IE 9. Maybe we should skip that test if FormData is unavailable?
This isn't the right level for this patch. Sites that want to support IE9 need to pass in uppercase method verbs. The polyfill needs to pass the argument through to the XHR untouched.