Action 1500 - fixed zoom

https://www.w3.org/WAI/PF/Group/track/actions/1500

I was given a couple of use cases where I think this is legitimate. 1) is a game like Cut the Rope, where multi-touch is used for game interaction rather than zooming. 2) is Bing Maps, where the default zooming behavior is disabled and the app has created custom zooming behavior in javascript. I still worry about authors misusing this for 'normal' apps where users would expect zooming. I think WCAG failures/techniques are probably the best path here. I will also look into documenting accessibility concerns for these features in MSDN.

IE supports the following ways to disable zooming.
* <meta name="viewport" content="user-scalable=no">
* <meta name="viewport" content="minimum-scale=1, maximum-scale=1">
* document.addEventListener("touchmove", function(e) {e.preventDefault()})
* html { touch-action: none; }
* html { -ms-content-zoom-limit-min: 1; -ms-content-zoom-limit-max: 1; }