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/ProjLib/ProjLib.cdl

@@ -80,16 +80,9 @@ is
 
 
     class ProjectOnPlane ;
-	---Purpose: Project a curve on a plane.
-
 
     class ProjectOnSurface ;
-	---Purpose: Project a curve on a  surface.  The result ( a  3D
-	--          Curve)  will be an approximation
 
- 
- 
- 
     -- ---------------------------------------------------------------
     --  Classes computing the PCurves of  curves lying on a surface
     --  
@@ -98,24 +91,10 @@ is
 
 
     class ComputeApprox;
-    	---Purpose: Approximate the  projection of  a 3d curve   on an
-	--          analytic surface and stores the result in Approx.
-	--          The result is a 2d curve.
-
 
     class ComputeApproxOnPolarSurface ;
-	---Purpose: Approximate the  projection  of a  3d curve  on an
-	--          polar  surface  and  stores the result  in  Approx.
-	--          The result is a  2d curve.  The evaluation of  the
-	--          current  point of the  2d  curve is done with  the
-	--          evaluation of the extrema  P3d - Surface.
-
 
     class ProjectedCurve ;
-    	---Purpose: Compute the 2d-curve.  Try to solve the particular
-    	--          case if possible.  Otherwize, an approximation  is
-    	--          done.
-
 
     class HProjectedCurve instantiates 
     	GenHCurve2d from Adaptor2d (ProjectedCurve);
@@ -147,22 +126,16 @@ is
     --  ------------------------------------------------------------
 
     class Projector;
-	---Purpose: Root class for projections. Stores the result.
-    
+
     class Plane;
-	---Purpose: Projection on a plane.
 
     class Cylinder;
-	---Purpose: Projection on a cylinder.
 
     class Cone;
-	---Purpose: Projection on a cone.
 
     class Sphere;
-	---Purpose: Projection on a sphere.
 
     class Torus;
-	---Purpose: Projection on a torus.
 
 
     -- methods

src/ProjLib/ProjLib_ComputeApprox.cdl

@@ -15,7 +15,9 @@
 -- commercial license or contractual agreement.
 
 class ComputeApprox from ProjLib 
-
+    ---Purpose: Approximate the  projection of  a 3d curve   on an
+	--          analytic surface and stores the result in Approx.
+	--          The result is a 2d curve.
 
 uses
      HCurve       from Adaptor3d,

src/ProjLib/ProjLib_ComputeApproxOnPolarSurface.cdl

@@ -15,7 +15,11 @@
 -- commercial license or contractual agreement.
 
 class ComputeApproxOnPolarSurface from ProjLib 
-
+	---Purpose: Approximate the  projection  of a  3d curve  on an
+	--          polar  surface  and  stores the result  in  Approx.
+	--          The result is a  2d curve.  The evaluation of  the
+	--          current  point of the  2d  curve is done with  the
+	--          evaluation of the extrema  P3d - Surface.
 
 
 uses

src/ProjLib/ProjLib_ProjectOnSurface.cdl

@@ -15,7 +15,8 @@
 -- commercial license or contractual agreement.
 
 class ProjectOnSurface from ProjLib 
-
+	---Purpose: Project a curve on a  surface.  The result ( a  3D
+	--          Curve)  will be an approximation
 uses
 
     HCurve       from Adaptor3d,

src/ProjLib/ProjLib_ProjectedCurve.cdl

@@ -15,8 +15,9 @@
 -- commercial license or contractual agreement.
 
 class ProjectedCurve from ProjLib inherits Curve2d from Adaptor2d 
-    
-
+    ---Purpose: Compute the 2d-curve.  Try to solve the particular
+    --          case if possible.  Otherwize, an approximation  is
+    --          done.
 
 uses