Throwing stuff in Demo Lvl

Put prefabs on stuff and put stuff in lvl. Things changed include:
streetlights are now prefabs and they're all in there; house light on
house 1 is tied to trashcan, demo trashcans have been put out in front
of house 0 to showcase the different stages; fog and fireflies have been
added to starter section of the demo lvl; cache prefab has been dropped
in demo lvl.