Improve Property constructors

When you create a Property with an object pointer and two method pointers, which aren't declared in the same class (e.g. in a base class), the automatical type deduction fails.
So instead of
`Property("value", object, &Class::getter, &Class::setter)`
you have to write `Property("value", object, &Class::getter, &Class::setter)`

Search the repository for the Property constructors and the existing type-deduction tests or examples; start by reproducing the base-class getter/setter case from the issue. Done means the constructor can deduce the needed type for that case without explicitly writing Property, with existing behavior still covered by tests.

Written by the indexing model from the issue text.