[ug] Remove definition of SMALL_D

The defintion fixes a missing include within dune-uggrid.

dune/grid/uggrid/ugwrapper.hh

@@ -8,9 +8,6 @@
 
 #include <dune-uggrid-config.hh> // DUNE_UGGRID_HAVE_DDDCONTEXT, ModelP
 
-/** \todo Here only to provide the constant DBL_EPSILON.  There's maybe a better way? */
-#include "float.h"
-
 namespace Dune {
 
   /** \brief Encapsulates a few UG methods and macros
@@ -929,9 +926,6 @@ namespace Dune {
       using UG_NAMESPACE ::DOUBLE_VECTOR;
       using UG::DOUBLE;
       double det;
-#ifndef SMALL_D
-      const double SMALL_D = DBL_EPSILON*10;
-#endif
       INVERSE_TRANSFORMATION(n, x, local, mat, det);
       return 0;
     }