[ODE] HashSpace bug?

[Mark Williams]

Lines 497-502 of collision_space.cpp (ODE 0.8) show that HashSpaces are 
likely to needlessly crash when dealing with large numbers of objects, 
because the direct alloca() call (rather than using the ALLOCA macro) 
there can quite easily exceed the stack size.

I've also noticed that defining dUSE_MALLOC_FOR_ALLOCA will in many 
cases leak large amounts of memory.



Cheers,
Mark