Added testfiles
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:
  PreCompose now complete.
  PreCompose method.
  Propagation of can compute to generalized morphism category.
  Necessary changes to propagate knowledge to generalized morphism.
  Fixed example.
  Second example for PreCompose of generalized morphisms.
Fixed bug in Install.