Fix: Issue 1785 - IE11 - Requiring mixed content never resolves or errors

[davedoran]

#1785

Websites served over HTTPS will refuse to load HTTP urls by default.

While all browsers reject an attempt to require([ 'http://some/module' ]), the timing is different on IE.

IE throws an error when adding the node.src attribute
Other browsers error out when appending the node to the DOM.

In the Chrome/FF/Safari/etc... scenario, the error callback is triggered and the error is reported.
For IE, the script tags are never a part of the DOM and the callbacks for load or error are not invoked. The result is an unhandled exception coming from requirejs and the calling code is never notified of the failure.

The Fix

Try/Catch around the action of adding the node.src, and notify the caller of the script error.

[jsf-clabot]

All committers have signed the CLA.

[ddziaduch]

@davedoran the CI has failed