more naming convention

now there are spawn objects!
now entity spawns are loaded from level!
now entity spawns are saved to level!

code/entity.lua

@@ -179,7 +179,7 @@ function Entity:getCollidingAt(x,y,object)
 		and y + self.box.from.y < collision.to.y
 		and y + self.box.to.y > collision.from.y
 		then
-			collision.isColliding = true
+			collision.is_colliding = true
 			return collision
 		end
 	end