Shuffle some updating code around specifically to fix the simulation stepping forward by the loading time (i.e. activity starting at 13:00:00 ends up starting at 13:00:15 because it took 15s to load) and simplify the minimised handling.
git-svn-id: http://svn.uktrainsim.com/svn/openrails/trunk@742 a9f3cfff-6c41-7446-b0ca-052bd761e6eb