Exposed checkResize() function through API

The setTimeout of jRespond caused a Race-Condition in my app, whereby rendering would sometimes be incorrect.  My solution was to explicitly call checkResize via jRespond just before getting the current breakpoint (to ensure the breakpoint was up-to-date and accurate), and that meant I had to expose the checkResize() method externally.  In either case, exposing it lends more power to the API, which may be useful for others too.