New propsets, added comment support

Added comment support for propset data files, comments for lines can be
placed after a ; character at the end of the line.

Split "default" into 3 different sets, "street", "trashcans" and
"warehouse". Very small set but it's a starting point for expansion, I
will eventually add some more objects to these sets as examples as well
as a different animation.

Added comments to all prop definitions.

Put all prop definitions into one file titled "all".