Get rid of include directives inside namespace blocks (bug #339).

Eigen/src/Eigen2Support/Geometry/AlignedBox.h

@@ -24,6 +24,8 @@
 
 // no include guard, we'll include this twice from All.h from Eigen2Support, and it's internal anyway
 
+namespace Eigen { 
+
 /** \geometry_module \ingroup Geometry_Module
   * \nonstableyet
   *
@@ -168,3 +170,5 @@ inline Scalar AlignedBox<Scalar,AmbiantDim>::squaredExteriorDistance(const Vecto
   }
   return dist2;
 }
+
+} // end namespace Eigen