updated=1372394902000 Parameter is basically the Unix epoch time in milseconds.
Your tile is being requested with a HTTP GET request. What you need to know about Http Get's is that you can pile on any arbitrary parameters at the end of a Get Request, and if the parameter does not make sense to the server, it will ignore it.
This fact is exploited often, to make sure that you get a new response from the server, and not from the Client Browser's cache.
If you had request for say: http://example.com/foo/bar.png, the browser would see if the resource from this url was present in the cache. If it is, then a request is Not made, and the resource is served from the cache.
Hence we tag an arbitrary parameter with the timestamp.Every time you make a new request, the timestamp has changed, and it becomes a new URL for the browser.
var ts=Math.round(new Date().getTime()/1000.0);
Hence Automatically, with every time your App runs, the new timestamp is used, and the latest tile is called.
A word of warning though: This will make your application slow, since none of the tiles will every be cached by your browser.