Create MCMC requirements
A new class needs to be implemented to represent "formal requirements" that allow to generate test suite with MCDC criteria.
This needs to be done in a new package af3.testing.mcmd
The class extends IfThenElse class (other solutions are possible but seems to be the cleanest for me).
It requires to check/enforce that branches can only be sequences of Assignments, i.e. there cannot be other IfThenElse (or any other complex behavior) inside the branches