requiredConstraintImpl extends the NoInheritanceSystemType
Merge branch 'master' of https://github.com/genericsystem/genericsystem2011
requiredConstraintIMpl
SingularConstraintImpl modifying the check
Merge branch 'master' of
https://github.com/genericsystem/genericsystem2011

Conflicts:
	genericsystem-impl/src/test/java/org/genericsystem/impl/RequiredConstraintTest.java
Merge branch 'master' of https://github.com/genericsystem/genericsystem2011
changing the checkconsistency to use check in each constraint sending
directly the instance and the constraintBase
Merge branch 'master' of
https://github.com/genericsystem/genericsystem2011

Conflicts:
	genericsystem-impl/src/main/java/org/genericsystem/constraints/InstanceClassConstraintImpl.java
changement size,singular and required constraint
checkconstraints
Merge branch 'master' of
https://github.com/genericsystem/genericsystem2011

Conflicts:
	genericsystem-impl/src/main/java/org/genericsystem/constraints/SizeConstraintImpl.java