more fixes towards working convex-convex, in case of (too) many edge-edge cases:

1) sample directions over a unit sphere and
2) add a contact, using mpr
add missing bullet.pc.cmake file (for old Bullet 2.x)

src/Bullet3OpenCL/NarrowphaseCollision/b3ConvexHullContact.h

@@ -27,6 +27,8 @@ struct GpuSatCollision
 	cl_command_queue		m_queue;
 	cl_kernel				m_findSeparatingAxisKernel;
 	cl_kernel				m_mprPenetrationKernel;
+	cl_kernel				m_findSeparatingAxisUnitSphereKernel;
+
 
 	cl_kernel m_findSeparatingAxisVertexFaceKernel;
 	cl_kernel m_findSeparatingAxisEdgeEdgeKernel;
@@ -57,6 +59,7 @@ struct GpuSatCollision
 
 	cl_kernel				m_processCompoundPairsPrimitivesKernel;
     
+	b3OpenCLArray<b3Vector3> m_unitSphereDirections;
 
 	b3OpenCLArray<int>		m_totalContactsOut;