Apply patches from 5c79896 on OCCT 6.7.0
Remove src/Image/Image_PixelAddress.cxx

This file should have been removed upstream in
 http://git.dev.opencascade.org/gitweb/?p=occt.git;a=commit;h=2361d7e
Revert an unneeded change in Plate_LinearScalarConstraint.cdl
Swap assignments to avoid compiler warnings
Fix prototype of debugCallbackWrap

Declaration in src/OpenGl/OpenGl_glext.h is:

  typedef void (APIENTRY *GLDEBUGPROCARB)(GLenum source,GLenum type,GLuint id,GLenum severity,GLsizei length,const GLchar *message,GLvoid *userParam);

OCCT 6.7.0 ships an updated version of glext.h, which has a different
signature (with respect to the last argument).  So maybe this change
will be reverted if glext.h is updated.
[warning-fix][ignored-qualifiers]
[warning-fix][unused-local-var]
[warning-fix][unused-function]
[warning-fix][declared-but-never-defined]
[warning-fix][extra-semi]
Bump OCCT version number in README.txt
[warning-fix][unused-local-var]
Fix build failure when compiling IntAna_Curve.cxx

This bug had been introduced when upgrading OCCT-patches
to OCCT 6.7.0.  We patched src/IntAna/IntAna_Curve.cxx
in c35fc63 to get rid of compiler warnings.
A different fix has been applied in OCCT 6.7.0, the
final return has been dropped, so our change has to
be removed from
  patches/submitted/thread_21388/warning/fix-uninitialized-var.patch
Fix precompiled headers, Image.hxx has been removed from OCCT 6.7.0
Fix bug introduced in 8646fb3

Many boolean operations did not behave as expected.
Merge pull request #446 from tpaviot/review/upgrade-OCCT-6.7.0

Upgrade to OCCT 6.7.0