Fix detection of activex support to work in IE11

[szekerest]

No description provided.

[ahocevar]

Thanks! Can you confirm that tests still pass with this in major browsers, including IE8?

One improvement suggestion: It would even be nicer to only detect this once, e.g.

OpenLayers.Format.XML.useActiveX = (function() {
    return (Object.getOwnPropertyDescriptor &&
            Object.getOwnPropertyDescriptor(window, "ActiveXObject")) ||
            ("ActiveXObject" in window);
})();

Or maybe even without the anonymous function.

[szekerest]

Tested the approach in Chrome, Firefox and IE11.
Need to find a PC which runs IE8.

[ahocevar]

Let me see if I can find that old WinXP VM of mine...

[ahocevar]

Works fine in IE8. @szekerest, are you able to implement the improvement I suggested above, and also use OpenLayers.Format.XML.useActiveX in OpenLayers.Format.WPSExecute#write(), like @bkiselka did?

[szekerest]

@ahocevar Modified the pull

[ahocevar]

Thanks for the continued effort on this @szekerest. Can you please submit a CLA so we can merge this?

[szekerest]

@ahocevar Signed