implement deepmimic reward function (only joint angles/velocities for now) fix an out-of-date comment, related to contactPoint.m_lateralFrictionInitialized in btSequentialImpulseConstraintSolver.cpp
implement deepmimic reward function (only joint angles/velocities for now) fix an out-of-date comment, related to contactPoint.m_lateralFrictionInitialized in btSequentialImpulseConstraintSolver.cpp