GitLab

- new ClassifySurfaces command in .geo files
- apply same workflow in classifySurfaces as in the interactive classification editor
- don't call createTopology in createGeometry anymore
- use STL in t13

full pass on the documentation to clarify general concepts, introduce the API and mention the new algorithms (including parallel features)

- added createTopology and createGeometry in api
- renamed symmetry (symmetrize), homology (computeHomology) and cohomology (computeCohomology): all api functions should be verbs