COMP: Future proof vnl_math_XXX function usage.

Prefer C++ over aliased names vnl_math_[min|max] -> std::[min|max]
Prefer vnl_math::abs over deprecated alias vnl_math_abs

In all compilers currently supported by VXL, vnl_math_[min|max]
could be replaced with std::[min|max] without loss of
functionality.  This also circumvents part of the backwards
compatibility requirements as vnl_math_ has been recently
replaced with a namespace of vnl_math::.

Since Wed Nov 14 07:42:48 2012:
The vnl_math_* functions use #define aliases to their
vnl_math::* counterparts in the "real" vnl_math:: namespace.

The new syntax should be backwards compatible to
VXL versions as old as 2012.

Prefer to use itk::Math:: over vnl_math:: namespace

include/itkSimoncelliIsotropicWavelet.hxx

@@ -50,12 +50,12 @@ SimoncelliIsotropicWavelet< TFunctionValue, VImageDimension, TInput >
 ::EvaluateMagnitude(const FunctionValueType & freq_norm_in_hz) const
 {
   // freq_in_rad_per_sec = freq_norm_in_hz * 2 * pi
-  // Dev: std::log2 is c++11 only.  std::log2(x) = std::log(x)/vnl_math::ln2
+  // Dev: std::log2 is c++11 only.  std::log2(x) = std::log(x)/itk::Math::ln2
   if ( freq_norm_in_hz > 0.125 && freq_norm_in_hz <= 0.5 )
     {
     return static_cast< TFunctionValue >(
         std::cos( 0.5 * Math::pi
-          * std::log(4 * freq_norm_in_hz) / vnl_math::ln2 ) );
+          * std::log(4 * freq_norm_in_hz) / itk::Math::ln2 ) );
     }
   return 0;
 }

include/itkVowIsotropicWavelet.hxx

@@ -53,12 +53,12 @@ VowIsotropicWavelet< TFunctionValue, VImageDimension, TInput >
 ::EvaluateMagnitude(const FunctionValueType & freq_norm_in_hz) const
 {
   // freq_in_rad_per_sec = freq_norm_in_hz * 2 * pi
-  // Dev: std::log2 is c++11 only.  std::log2(x) = std::log(x)/vnl_math::ln2
+  // Dev: std::log2 is c++11 only.  std::log2(x) = std::log(x)/itk::Math::ln2
   if ( freq_norm_in_hz >= 1 / 8.0 && freq_norm_in_hz < 1 / 4.0 )
     {
     return static_cast< TFunctionValue >(
       sqrt(0.5
-        + std::tan(this->m_Kappa * (1.0 + (2.0 / vnl_math::ln2) * std::log(4 * freq_norm_in_hz)))
+        + std::tan(this->m_Kappa * (1.0 + (2.0 / itk::Math::ln2) * std::log(4 * freq_norm_in_hz)))
         / (2.0 * std::tan(this->m_Kappa)))
       );
     }
@@ -67,7 +67,7 @@ VowIsotropicWavelet< TFunctionValue, VImageDimension, TInput >
     {
     return static_cast< TFunctionValue >(
       sqrt(0.5
-        - std::tan(this->m_Kappa * (1.0 + (2.0 / vnl_math::ln2) * std::log(2 * freq_norm_in_hz)))
+        - std::tan(this->m_Kappa * (1.0 + (2.0 / itk::Math::ln2) * std::log(2 * freq_norm_in_hz)))
         / (2.0 * std::tan(this->m_Kappa)))
       );
     }