IE9 fails on new CustomEvent when in standards mode

[rmowder]

CustomEvent actually exists natively in IE9 when in standards mode however it fails when used so even though it exists it needs to be replaced with the polyfil code.

new CustomEvent('evt'); // results in "Object doesn't support this action"

this condition is the culprit @ line 127

!this.CustomEvent && (function(){ 
    // your code here
 })()

if can be augmented to the following (or similar) to resolve the issue

try {new window.CustomEvent('?')} catch(e) {
  // your code here
}

a similar check should be added around the CustomEvent defineGetter declaration