For version 4.0 (over 3.0)

New features:
 - dmClosedArticulation, dmSecondaryForce, dmSecondaryJoint, etc classes for
     closed chain simulation
 - new dmQuaternionLink with 3 revolute DOFs (link dmSphericalLink only
     more robust)
 - new dmStaticRootLink to move the reference system to new location
 - Added ability to simulate accurately across contact boundaries (changes to
     contact model, forces, and integrators).
 - Made dmSystem a base class for generic dynamic systems that need to be
     simulated (base class for dmArticulation and dmEnvironment).
 - Added ability of a single dmIntegrator to numerically integrate more than
     one dmSystem
 - Added a dynamic environment: dmTreadmill
 - Added Dev Studio Workspace and Project files