Added polyfills and new build for legacy support.

- Created support folder to store all polyfills.
- Updated code to include the new polyfills where required.
- By default, ignore the support modules.
- Build a legacy file with the support built in.
Full IE support, back to IE 7.

I can only test this far, since IE 9 doesn't emulate IE 6.  I've added
the remaining polyfills and tested.
Only run Sauce Labs, not npm test as well.
Removing a useless test.
Adding final browsers.
Merge pull request #20 from tbranyen/ie-fixes

IE Fixes.