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/StdSelect/StdSelect.cdl

@@ -91,20 +91,11 @@ is
 
 
     class ViewerSelector3d;
-    	---Purpose: Viewer Selector for a view from V3d
-    	--          Accepts Only Sensitive Entities inheriting Select3D entities...
-    
-    
-    
+
     class BRepSelectionTool;
-    	---Purpose: gives standard selections for Shapes
 
     class BRepOwner;
-    	---Purpose: Owner classes for BRep objects 
-	--          used by BRepSelectionTool to know which entities
-	--          own the sensitive primitives created.
-	--          the hilight-unhilight methods are empty and
-	--          must be redefined by each User...
+
 
     ---Category: Shape Filters
 

src/StdSelect/StdSelect_BRepOwner.cdl

@@ -21,6 +21,8 @@ class BRepOwner from StdSelect inherits EntityOwner from SelectMgr
 	--          Used in Dynamic Selection Mechanism.
 	--          A BRepOwner has an Owner (the shape it represents)
 	--          and Users (One or More Transient entities).
+	--          The highlight-unhighlight methods are empty and
+	--          must be redefined by each User.
 
 uses
     Location              from TopLoc,

src/StdSelect/StdSelect_ViewerSelector3d.cdl

@@ -19,6 +19,7 @@
 class ViewerSelector3d from StdSelect inherits ViewerSelector from SelectMgr
 
     ---Purpose: Selector Usable by Viewers from V3d
+    --          Accepts Only Sensitive Entities inheriting Select3D entities...
 
 uses
     View                 from V3d,