physics, parser: added random mode, memory allocation is now exact

Whoa, mega update! Random mode spawns X amound of objects with random velocities at random places. Memory allocation - now exact: no more obj+a few thousand just to be safe! Now we allocate precisely what we need. Also... BOND ARRAY IS DYNAMICALLY ALLOCATED AS WELL! It was that simple. Though I still don't know if it's a good idea to do it.