it compiles (again)

Noteworthy only because its been a few weeks, PySoy is compiling once again.

Also took care of those ugly warnings on soy.bodies, a result of ODE using const and Pyrex not. The solution was listed in the Pyrex docs, just a matter of finding it and plugging in the explicit typecast.

More work is needed on the Screen and Window classes before it can display anything. The freeglut->glx transition process is wrapping up but isn't finished yet.