DynamicKernel isn't needed outside formulagroupcl.cxx after all

So put it back there.

Change-Id: I7c78719c95123e33e4506ace912ff056df56b247
opbase.hxx and clew.h can now move back where they were, too

Change-Id: I0037eed4102eebafdab3c8b5dc6a3d92b57bd49b