Enhancement of the OCC interface

occ mingw

small fixes to cgns + occ win

support for CGNS IO

added FORMAT_CGNS

comment

a start on CGNS IO

removed some unused functors

new != operator
removed some unused functors

added GModelIO_CGNS.cpp

Added CGNS IO

Plane surfaces are now recognized and the
usual gmsh "cross" is drawn correctly

occ dvlpt

occ work

fix surfperiodic

more occ work

more occ work

:i

occ work

more occ work

occ work