make glib2 work on debian 6 (build libffi, build pkg-config)
tweak pkg-config detection. also fix weird gcc4.5 problem w NefPoly
undo nef poly 'fix', wasnt a fix
fix build gcc 4.5 (CGAL ENABLE during DEBUG of Geometry Cache)
fix build on gcc 4.5 (typedef typename is c++0x)