Put back in the OVERRIDE_11 macro in Doxyfile.
Put back in the OVERRIDE_11 macro in Doxyfile.

[ci skip]
opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core