DomainAssociatedMorphismCodomainTriple

implemented special cases.
Merge branch 'master' of https://github.com/sebasguts/CategoriesForHomalg

* 'master' of https://github.com/sebasguts/CategoriesForHomalg:
  Renamed EqualityOfMorphisms -> IsEqualForMorphisms
Documentation: AddF

for a functionname F
Renamed AddKernel -> AddKernelObject
Renamed AddImage -> AddImageObject
Renamed: AddPullback -> AddFiberProduct
Unique names for ProjectionInFactorOfX

X = Pullback
or
X = DirectProduct

Of course both methods still can be called by the convenient method
ProjectionInFactor.
InjectionOfCofactorOfX

X = Pushout or
X = Coproduct
Renamed

ProjectionInFactorWithGivenDirectProduct ->
ProjectionInFactorOfDirectProductWithGivenDirectProduct
Renamed

InjectionOfCofactorWithGivenCoproduct ->
InjectionOfCofactorOfCoproductWithGivenCoproduct
Convenience

for InjectionOfCofactorOfCoproduct
Adjusted CanComputes and Functions

of InjectionOfCofactorOfCoproduct
and ProjectionInFactorOfDirectProduct
Wrote first version of system to apply theorems to deduction system.