CORS and IE6 Support

CORS detection was still not quite right in a couple places so we were detecting non-CORS as CORS. Fixed that and set up the unit tests in a Tin Can package to allow testing non-CORS easily which allowed me to get to an IE6 test such that I could try to add support for it. So did and it appears to work. Unit tests pass in IE6 launched from SCORM Cloud with one anomaly which shouldn't affect Tin Can support so I'm ignoring it for the moment.

Tested in:
 
- [x] Chrome
- [x] FireFox
- [x] Safari
- [x] IE 10
- [x] IE 9
- [x] IE 8
- [x] IE 7
- [x] IE 6