Added stv to be-inheritance-rule
Added example to clarify use case of be-inheritance-rule

As requested by @amebel
Added stv of 1.0 1.0 to SVO rule

Before, produced EvaluationLink had a confidence of 0, so PLN wasn't able to recognize it.
Merge pull request #777 from sebastianruder/be_inheritance_stv

Making the Socrates demo work