MAJOR improvements to picking up objects

You can also throw things by clicking on them for just a second.  It's
fun.
Turns out I didn't fix the freezing glitch last commit.   It is now
fixed in most cases, but not when the object is lifted and then held
still for a few seconds.
Entities are now btMotionStates

so graphics is supafast.
Now it really looks like othello

Also put in harness for rendering collision meshes
Added mouse shadow and laser guide
Added mouse shadow, laser guide, and wireframe

press r for wireframe.
Moved mouse pointer and made its height a #define

#hashtag #poundsign