Tag to be used with the main branch of atlas/athena. Update(s) since 2.1.6: - Updated atlas_add_dictionary(...) to generate "SG::AuxTypeVectorFactoryImpl<ElementLink<T> >" dictionaries for the types in its ELEMENT_LINK argument; - Updated GeoModel to version 4.6.0; - Introduced the FindSFGen.cmake module to AtlasLCG; - Introduced VecMem as an external, and added it to the build of AthenaExternals.