Generalized direct products
Merge branch 'master' of momo.mathb.rwth-aachen.de:/home/gutsche/gap/repos.git/CategoriesForHomalg

* 'master' of momo.mathb.rwth-aachen.de:/home/gutsche/gap/repos.git/CategoriesForHomalg:
  Documentation for InstallWithToDo etc.
Implemented direct product functor
Eliminated direct product for 2 arguments from the code
Documentation of direct products
Declare*With* can now be documented via autodoc.