+ improved friction warm starting
+ made constraint solver configuration more consistent (moved m_solverMode into btContactSolverInfo)
+ reset timing in CDTestFramework after initialization (SAP init destorts timings)
+ make it easier to change default sizes for stack allocator in btDefaultCollisionConfiguration
+ fixed issue with persistent manifold, warmstarting values were not initialized properly
+ don't clear manifold in sphere-sphere collision (need warmstarting)
+ added support for 'split impulse', decouple positional error correction from velocity correction
This avoids adding momentum due to penetration correction, it can be tuned using following variables:
solverInfo.m_splitImpulse = true/false (disable/enable)
solverInfo.m_splitImpulsePenetrationThreshold (below this value, baumgarte/mixed velocity/penetration is used (cheaper, looks more plausible)
solverInfo.m_linearSlop (less jitter, when small amound of penetration is allowed)