remove redundant/wrong glClear

always initialize mpr OpenCL kernels
add a second ragdoll to the demo

src/Bullet3OpenCL/NarrowphaseCollision/b3ConvexHullContact.cpp

@@ -135,7 +135,6 @@ m_unitSphereDirections(m_context,m_queue)
 //		sprintf(flags,"-g -s \"%s\"","C:/develop/bullet3_experiments2/opencl/gpu_narrowphase/kernels/sat.cl");
 //#endif
 		m_mprPenetrationKernel  = 0;
-		if (useMprGpu)
 		{
 			cl_program mprProg = b3OpenCLUtils::compileCLProgramFromString(m_context,m_device,mprSrc,&errNum,flags,BT_NARROWPHASE_MPR_PATH);
 			b3Assert(errNum==CL_SUCCESS);