add experimental ram-only emulua savestate code. now call savestate_persist(ss) if you want to cause it to go to disk. otherwise it will stay in memory. this might speed things up. also add experimental new ppu which can be enabled by newppu 1 in configfile. there is no reason to use it yet but i needed to do a checkin
- loading script does an implicit stop first
- script dying of natural causes triggers a stop, and thus an OnStop event in lua first (for proper cleanup)