Switched Muscle equilibrate method to invoke computeFiberEquilibriumAtZeroVelocity() instead of computeInitialFiberEquilibrium. For concrete muscles these are the same except for the Millard2012EquilibriumMuscle, which is trying to distribute non-zero muscle-tendon velocity and is failing in some instances of high velocity. The static case is safer.
Switched Muscle equilibrate method to invoke computeFiberEquilibriumAtZeroVelocity() instead of computeInitialFiberEquilibrium. For concrete muscles these are the same except for the Millard2012EquilibriumMuscle, which is trying to distribute non-zero muscle-tendon velocity and is failing in some instances of high velocity. The static case is safer.

git-svn-id: 9e047e1e624cce0a2485e750063112e834f85522@8649 fc29be9c-2cb0-420d-b520-73dbd18add6e

opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core