change rx/ry to radiusX/radiusY, set default to 1 if no value known

Author: shepazu

touchevents.html

@@ -124,13 +124,13 @@ <h2><dfn>TouchPoint</dfn> Interface</h2>
           y-coordinate of point relative to the viewport, including any scroll offset
         </dd>
 
-        <dt>readonly attribute float rx</dt>
+        <dt>readonly attribute float radiusX</dt>
         <dd>
-          the radius of the ellipse which most closely circumscribes the touching area (e.g. finger, stylus) along the x-axis, in pixels
+          the radius of the ellipse which most closely circumscribes the touching area (e.g. finger, stylus) along the x-axis, in pixels; <code>1</code> if no value is known
         </dd>
-        <dt>readonly attribute float ry</dt>
+        <dt>readonly attribute float radiusY</dt>
         <dd>
-          the radius of the ellipse which most closely circumscribes the touching area (e.g. finger, stylus) along the y-axis, in pixels
+          the radius of the ellipse which most closely circumscribes the touching area (e.g. finger, stylus) along the y-axis, in pixels; <code>1</code> if no value is known
         </dd>