Add a todo for strange brief descriptions.

Circular_kernel_2/doc/Circular_kernel_2/Concepts/AlgebraicKernelForCircles--ConstructPolynomial_1_2.h

@@ -3,6 +3,10 @@
 \ingroup PkgCircularKernel2AlgebraicConcepts
 \cgalconcept
 
+\todo Concepts starting like this should have a specific or empty
+brief description and should place "A model..." after see also or drop
+the sentence all together.
+
 A model `fo` of this type must provide: 
 
 \sa `CircularKernel::ConstructLine_2`

Circular_kernel_2/doc/Circular_kernel_2/Concepts/CircularKernel--ConstructCircularMinVertex_2.h

@@ -10,9 +10,6 @@ A model `fo` of this type must provide:
 class CircularKernel::ConstructCircularMinVertex_2 {
 public:
 
-/// \name See Also 
-/// @{
-
 /*! 
 Constructs the `x`-minimal vertex of `c`. 
 \pre The arc `c` is `x`-monotone. 
@@ -26,7 +23,5 @@ Same, for a line segment.
 CircularKernel::Circular_arc_point_2 operator() 
 (const CircularKernel::Line_arc_2 & l); 
 
-/// @}
-
 }; /* end CircularKernel::ConstructCircularMinVertex_2 */
 

Circular_kernel_2/doc/Circular_kernel_2/Concepts/CircularKernel--DoOverlap_2.h

@@ -5,6 +5,7 @@
 
 Testing whether the interiors of two curves overlap. 
 
+\bug There is no DoOverlap in the Linear Kernel.
 \refines ::Kernel::DoOverlap_2 
 
 */