Some cleanups regarding WellDefined
WellDefined Fixup in Opposite
Some more WellDefined fixups.
Merge branch 'master' of https://github.com/sebasguts/CategoriesForHomalg

* 'master' of https://github.com/sebasguts/CategoriesForHomalg:
  Some more WellDefined fixups.
  WellDefined Fixup in Opposite
  Some cleanups regarding WellDefined

Conflicts:
	gap/GeneralizedMorphismCategory.gi