make demo start/stoppable, avoids unneccessary load on browser/demoserver
make demo start/stoppable, avoids unneccessary load on browser/demoserver

git-svn-id: de585c8a1036fae0bde8438f23c67a99526c94d0@623 286bb87c-ec97-11de-a004-2f18c49ebcc3

rctk/demos