DOC: doxygen does not process specialization of few classes.

Introduce HIDE_SPECIALIZATION_DOCUMENTATION as conditional section for
doxygen. If one is interested in it, we only need to add to the list
of ENABLED_SECTION in the doxygen configuration file.

Here is a typical usage:

/** \cond HIDE_SPECIALIZATION_DOCUMENTATION */
template<>
class MyClass< bool >
{};
/** \endcond */

Change-Id: I05a563449c257e4cd3a321743c9235f50302af53

Modules/Core/Common/include/itkNumericTraits.h

@@ -125,6 +125,7 @@ class NumericTraits:public vcl_numeric_limits< T >
   static T min(const T & val) { return TraitsType::min(); }
 };
 
+/** \cond HIDE_SPECIALIZATION_DOCUMENTATION */
 
 /** \class NumericTraits<bool>
  * \brief Define traits for type bool.
@@ -678,6 +679,9 @@ class NumericTraits< unsigned long long > :
   static ValueType ZeroValue() { return Zero; }
   static ValueType OneValue() { return One; }
 };
+
+/** \endcond */
+
 } // end namespace itk
 
 #include "itkFixedArray.h"

Modules/Core/Common/include/itkPixelTraits.h

@@ -51,6 +51,8 @@ class PixelTraits
   typedef typename TPixelType::ValueType ValueType;
 };
 
+/** \cond HIDE_SPECIALIZATION_DOCUMENTATION */
+
 /** \class PixelTraits<bool>
  * Specialization of PixelTraits for scalar images. */
 template< >
@@ -149,6 +151,8 @@ class PixelTraits< double >
   typedef double ValueType;
 };
 
+/** \endcond */
+
 /** \class JoinTraits
  * \brief Trait to determine what datatype is needed if the specified
  * pixel types are "joined" into a single vector.
@@ -173,6 +177,8 @@ class JoinTraits
   typedef TValueType1 ValueType;
 };
 
+/** \cond HIDE_SPECIALIZATION_DOCUMENTATION */
+
 /** \class JoinTraits
  * Specializations for bool. */
 template< >
@@ -1047,6 +1053,9 @@ class JoinTraits< double, double >
 public:
   typedef double ValueType;
 };
+
+/** \endcond */
+
 } // end namespace itk
 
 #endif // __itkPixelTraits_h

Modules/Filtering/MathematicalMorphology/include/itkMorphologyHistogram.h

@@ -189,6 +189,7 @@ class VectorMorphologyHistogram
   TInputPixel                     m_Boundary;
 };
 
+/** \cond HIDE_SPECIALIZATION_DOCUMENTATION */
 
 // now create MorphologyHistogram partial specilizations using the VectorMorphologyHistogram
 // as base class
@@ -211,6 +212,8 @@ class MorphologyHistogram<bool, TCompare>:
 {
 };
 
+/** \endcond */
+
 } // end namespace Function
 } // end namespace itk
 

Modules/Filtering/MathematicalMorphology/include/itkMovingHistogramMorphologicalGradientImageFilter.h

@@ -179,6 +179,8 @@ class VectorMorphologicalGradientHistogram
   SizeValueType                m_Count;
 };
 
+/** \cond HIDE_SPECIALIZATION_DOCUMENTATION */
+
 // now create MorphologicalGradientHistogram specilizations using the VectorMorphologicalGradientHistogram
 // as base class
 
@@ -200,6 +202,8 @@ class MorphologicalGradientHistogram<bool>:
 {
 };
 
+/** \endcond */
+
 } // end namespace Function
 
 /**

Modules/Nonunit/Review/include/itkRankHistogram.h

@@ -389,6 +389,8 @@ class VectorRankHistogram
 // now create MorphologicalGradientHistogram specilizations using the VectorMorphologicalGradientHistogram
 // as base class
 
+/** \cond HIDE_SPECIALIZATION_DOCUMENTATION */
+
 template<>
 class RankHistogram<unsigned char>:
   public VectorRankHistogram<unsigned char>
@@ -407,6 +409,8 @@ class RankHistogram<bool>:
 {
 };
 
+/** \endcond */
+
 } // end namespace Function
 } // end namespace itk
 #endif

Modules/Numerics/Statistics/include/itkMeasurementVectorTraits.h

@@ -443,6 +443,7 @@ class MeasurementVectorPixelTraits
   typedef TPixelType MeasurementVectorType;
 };
 
+/** \cond HIDE_SPECIALIZATION_DOCUMENTATION */
 template< >
 class MeasurementVectorPixelTraits< char >
 {
@@ -519,6 +520,9 @@ class MeasurementVectorPixelTraits< double >
 public:
   typedef FixedArray< double, 1 > MeasurementVectorType;
 };
+
+/** \endcond*/
+
 } // namespace Statistics
 } // namespace itk