0020948: EDF 1468 SMESH: Histogram of the quality controls

0020948: EDF 1468 SMESH: Histogram of the quality controls
   move updating distrubution of scalar bar to SMESH_Actor::UpdateDistribution()
+  virtual void SMESH_Actor::UpdateDistribution() = 0;

0020944: EDF 1464 SMESH: detection of over-constrained elements
+    class  OverConstrainedVolume: public Predicate
+    class  OverConstrainedFace: public Predicate