[ODE] CFM not global

[Rafael Horbach]

I need to use a cfm per body, for the following reason:

I have a body with ball joints connecting boxes (a goal net, in fact). 
And to make it with a better behavior, I've increased the global CFM. It 
allows the net to bend in a natural way, by the gravity, and also when 
the ball hits it. But I have other ragdoll objects that have a poor 
behavior with that setting, so I guess I cannot use the same CFM 
(global) with all bodies.

So I think that I need to be able to set the CFM per body (or per 
joint?), so I've tried several things....

- SoftCFM is only used for contacts (not the case), so I'm ignoring it 
for now
- dParamCFM cannot be used with ball joints. Maybe I could change this?
- dParamSuspensionCFM I don't know exacly what this suspension means, 
but it is only implemented in hinge-2 joint

Another thing I'm thinking about is about creating a new setting, or 
implementing the cfm on the ball joint. But the fact is that I don't 
know for sure if the nice effect I had was due the bodies of the joints.

Any suggestions? Ideas? Thanks anyway ;)

Best Regards,
Rafael