[ODE] Yesterday's checkin

[Jeffrey Smith]

Last night, I checked in changed to the following files:
 include/ode/common.h
 include/ode/collision_trimesh.h
 include/ode/objects.h

 src/collision_trimesh.cpp
 src/collision_trimesh_intern
 src/collision_util.cpp
 src/error.cpp
 src/joint.cpp
 src/lcp.cpp
 src/ode.cpp
 src/odemath.cpp
 src/quickstep.cpp
 src/step.cpp

Most of these were minor changes and small bugfixes, but there are
two significant additions to ODE.  

I added some new functions that allow fully-functional joint attchment
between bodies and geoms.  Perviously, constraints attached to moving
geoms would stretch during their movement; you can now use the
functions:

 dJointSetBallAnchor2
 dJointSetHingeAnchorDelta
 dJointSetSliderAxisDelta

To update the location of a joint, without resetting the joint angle
counter and without "stretching" the constraint.

I also added an alternate memory allocation scheme to step.cpp and
lcp.cpp.  By turning on the switch dUSE_MALLOC_FOR_ALLOCA (in
common.h), the functions in "step.cpp" and "lcp.cpp" will use
malloc/free to allocate memory for vectors and arrays, rather than the
stack.  While slower, this allows you to simulate much larger systems.
Further, if an out-of-memory error is detected, the appropriate
functions fail gracefully (freeing memory along the way) and report an
error.

-Jeff