Preparation of substitution of data types

ProductCategoryMorphisms -> List of morphisms
ProductCategoryObjects -> List of objects
Step1  of data type exchange

modified UniversalObjects.g*
Step2 of type change

adjusted accurences of Products.
Removed products from deduction system, we are working with lists now.
Renamed AsDeductionSystem* -> InDeductionSystem
Renamed Deduction -> Deductive
Renamed files
Enhanced convenience methods
Merge remote-tracking branch 'Sepp/master'

* Sepp/master:
  Enhanced convenience methods
  Step2 of type change
  Step1  of data type exchange
  Preparation of substitution of data types