Brazen Alaska

Test for "blob:" in createObjectURL URLs for support

If URL.createObjectURL returns a URL that starts with something other
than "blob:", it can be assumed that the URL object has been
polyfilled by a library and there is no need to test further.

This addresses the environment created by Blob.js1 for Internet
Explorer and makes this check for "blob:" URL support fail as it should.

Initial Release

Add version and licensing comment to JS file

Fixes #2.