Merge pull request #74 from uzername/master

Some new information to developer's FAQ. That's my pull request.
Added a game message for veh-veh collisions.
rl_dist() correct usage
bounds checking before displace_vehicle,

stops vehicle & warns if somehow out of bounds.
partial fix for overly fun veh-veh happenings

After collision, normalize remaining time to move. This mostly prevents
another collision happening immediately afterwards, which had inverted the
resulting velocity due to an inverted normalized blah blah blah.
Some embellishments to the house