Fix incorrect radiusX/Y to width/height translation

Currently, in the case of touch, width/height use radiusX/radiusY, which
results in half the expected width/height (should be the diameters)

Closes gh-343

src/touch.js

@@ -146,8 +146,8 @@ var touchEvents = {
     e.detail = this.clickCount;
     e.button = 0;
     e.buttons = this.typeToButtons(cte.type);
-    e.width = inTouch.radiusX || inTouch.webkitRadiusX || 0;
-    e.height = inTouch.radiusY || inTouch.webkitRadiusY || 0;
+    e.width = (inTouch.radiusX || inTouch.webkitRadiusX || 0) * 2;
+    e.height = (inTouch.radiusY || inTouch.webkitRadiusY || 0) * 2;
     e.pressure = inTouch.force || inTouch.webkitForce || 0.5;
     e.isPrimary = this.isPrimaryTouch(inTouch);
     e.pointerType = this.POINTER_TYPE;