0024784: Move documentation in CDL files to proper location

Mostly duplicated comments were removed and missing ones were moved
into dedicated class CDL files.
Some more duplicated comments were removed from CDL files.
Correction of merge

src/DBRep/DBRep.cdl

@@ -41,27 +41,22 @@ uses
 
 is
 
-    class Edge; 
-	---Purpose: Display of an edge. Edge + color.
+    class Edge;
 	
     class ListOfEdge instantiates 
     List from TCollection(Edge from DBRep);
 
     class Face;
-	---Purpose: Display of a face. Face + Array of iso + color.
 	
     class ListOfFace instantiates 
     List from TCollection(Face from DBRep);
 
     class HideData;
-	---Purpose: Hidden lines data for a view
 
     class ListOfHideData instantiates
     List from TCollection(HideData from DBRep);
 
     class DrawableShape;
-	---Purpose: Drawable structure to display a  shape. Contains a
-	--          list of edges and a list of faces.
     
     class IsoBuilder;
 	---Purpose: Creation of isoparametric curves.

src/DBRep/DBRep_DrawableShape.cdl

@@ -15,7 +15,8 @@
 -- commercial license or contractual agreement.
 
 class DrawableShape from DBRep inherits Drawable3D from Draw
-    ---Purpose: 
+	---Purpose: Drawable structure to display a  shape. Contains a
+	--          list of edges and a list of faces.
 
 uses  
     Shape           from TopoDS,

src/DBRep/DBRep_Edge.cdl

@@ -15,7 +15,7 @@
 -- commercial license or contractual agreement.
 
 class Edge from DBRep inherits TShared from MMgt
-
+	---Purpose: Display of an edge. Edge + color.
 uses
     Edge    from TopoDS,
     Color   from Draw

src/DBRep/DBRep_Face.cdl

@@ -15,7 +15,7 @@
 -- commercial license or contractual agreement.
 
 class Face from DBRep inherits TShared from MMgt
-
+	---Purpose: Display of a face. Face + Array of iso + color.
 uses
     Face            from TopoDS,
     IsoType         from GeomAbs,