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/IntPolyh/IntPolyh_Intersection.cdl

@@ -23,7 +23,12 @@
 -- times.
 
 class Intersection from IntPolyh
-
+	---Purpose:  the main   algorithm.  Algorythm   outputs are
+	--           lines  and  points like   discribe   in the last
+	--           paragraph.  The Algorythm provides direct acces to
+	--           the elements of those   lines  and points. Other
+	--           classes  of this package  are for internal use and
+	--           only concern the algorithmic part.
 
 uses