Fix Memory Leak by re-scoping touchstart

Fix Memory Leak (detached DOM elements remaining in scope after destroy in a SPA app) by scoping the touchstart event to the children of this.$newElement -- which preserves the desired behavior while creating this event such that it will automatically be removed when "destroy" occurs.

This resolves issues 578 and 582.   Without this fix, in a SPA app, the DOM element remains in scope after destroy due to the touchstart handler.