Constraint Weight

A better way to control when the constraint is active is to use the constraint weight, instead of the NodeState which I used so far.

The expressions to do that look something like that:

ctlLeftFoot_orientConstraint1.j_LeftAnkleW0 =
     1 - ctlLeftFoot.UseIK;

and

ctlLeftFoot_pointConstraint1.j_LeftAnkleW0 = 
     1 - ctlLeftFoot.UseIK;

* Update: this doesn't work as expected. I'm going back to NodeState...