Merge pull request #12 from Chabrier/master

decision: Add a common ifValidName function
Decision: add a parameter to the predicate item

The predicate item has been enhanced. The signature of the predicate
function does accept a vle::value parameter, and the value is stored
inside the parameter object.
examples: fix the CMakeLists.txt file

A package name mismatch has been removed.
examples: update the decision examples

In order to propagate an update of the predicate system of the
decision extension, predicates bindings have been modified. A NULL
pointer is also passed.