Leverage touch-action whenever possible

Fixes ftlabs#498

lib/fastclick.js

@@ -801,7 +801,7 @@
 		}
 
 		// IE10 with -ms-touch-action: none or manipulation, which disables double-tap-to-zoom (issue #97)
-		if (layer.style.msTouchAction === 'none' || layer.style.touchAction === 'manipulation') {
+		if (layer.style.msTouchAction === 'none' || layer.style.msTouchAction === 'manipulation') {
 			return true;
 		}
 
@@ -817,9 +817,13 @@
 			}
 		}
 
-		// IE11: prefixed -ms-touch-action is no longer supported and it's recomended to use non-prefixed version
-		// http://msdn.microsoft.com/en-us/library/windows/apps/Hh767313.aspx
-		if (layer.style.touchAction === 'none' || layer.style.touchAction === 'manipulation') {
+		// Browsers that support touch-action can just use that to disable double-tap.
+		// https://developers.google.com/web/updates/2013/12/300ms-tap-delay-gone-away?hl=en
+		if ('touchAction' in layer.style) {
+			// Only 'auto' (the default) has double-tap enabled
+			if (layer.style.touchAction === '' || layer.style.touchAction === 'auto') {
+				layer.style.touchAction = 'manipulation';
+			}
 			return true;
 		}