BUG: workaround for dlclose issue #418

Avoid
Inconsistency detected by ld.so: dl-close.c: 737: _dl_close: Assertion
`map->l_init_called' failed!
when unloading application in the ApplicationEngine framework

This error is seen on Linux platform with gcc >= 4.5
and appears to be caused by STB_GNU_UNIQUE symbols
in the LineSegmentDetection application, a recent gcc feature.

nm otbapp_LineSegmentDetection.so | grep " u "
shows that these symbols comes from the use of Boost.Math
in Code/FeatureExtraction/otbLineSegmentDetector.txx
to compute some mathematical special functions values.

Those special functions are actually provided by netlib/slantec
in the ITK Utilities.

Code/FeatureExtraction/otbLineSegmentDetector.txx

@@ -18,8 +18,6 @@
 #ifndef __otbLineSegmentDetector_txx
 #define __otbLineSegmentDetector_txx
 
-#include <boost/math/special_functions/beta.hpp>
-
 #include "otbLineSegmentDetector.h"
 #include "itkImageRegionIterator.h"
 #include "itkNumericTraits.h"
@@ -38,6 +36,10 @@
 #include "itkMatrix.h"
 #include "itkSymmetricEigenAnalysis.h"
 
+
+extern "C" double dlngam_(double *x);
+extern "C" double dbetai_(double *x, double *a, double *b);
+
 namespace otb
 {
 
@@ -1018,12 +1020,20 @@ LineSegmentDetector<TInputImage, TPrecision>
   if (k == 0)
     return -logNT;
 
-  val = -logNT - log10( boost::math::ibeta(k_d, n_d - k_d + 1, p) );
+  double x = p;
+  double a = k_d;
+  double b = n_d - k_d + 1.0;
+  val = -logNT - log10( dbetai_(&p, &a, &b) );
 
   if (vnl_math_isinf(val)) /* approximate by the first term of the tail */
-    val = -logNT - (boost::math::lgamma(n_d + 1.0) - boost::math::lgamma(k_d + 1) - boost::math::lgamma(n_d - k_d + 1)) / CONST_LN10
-          - k_d * log10(p) - (n_d - k_d) * log10(1.0 - p);
+  {
+    double x1 = n_d + 1.0;
+    double x2 = k_d + 1.0;
+    double x3 = n_d - k_d + 1.0;
 
+    val = -logNT - (dlngam_(&x1) - dlngam_(&x2) - dlngam_(&x3)) / CONST_LN10
+          - k_d * log10(p) - (n_d - k_d) * log10(1.0 - p);
+  }
   return val;
 }