Necessary changes to propagate knowledge to generalized morphism.
Consistency for derived pullback/ pushout algrithms
Universal object genesis

first diagram won't be overwritten by other methods
Propagation of can compute to generalized morphism category.
CanComputeGeneralizedMorphismFromFactorToSubobject
PreCompose method.
Merge remote-tracking branch 'Sepp/master'

* Sepp/master:
  CanComputeGeneralizedMorphismFromFactorToSubobject
  Universal object genesis
  Consistency for derived pullback/ pushout algrithms