Merge branch 'feature_x3d_updates' into 'master'

doc/texinfo/opt_print.texi

examples/api/x3d_export.py

src/common/Context.h

src/common/CreateFile.cpp

src/common/DefaultOptions.h

src/common/Options.cpp

src/common/Options.h

src/geo/GModel.h

src/geo/GModelIO_X3D.cpp