MU-39 listActions() endpoint now filters actions by context.
[MU-36] New CandidateTypes module
[MU-36] add allowedCandidates property to existing actions
[MU-36] add allowedCandidate to existing predicates
[MU-36] add a rule getInconsistencies() method

This method checks the consistencies between the predicates and
the action:

* predicates and actions allowed candidates
* action predicates compatibility

It returns null if everything is alright, an array of inconsistencies
otherwise.