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

Eigen/src/Core/ArrayBase.h

@@ -25,6 +25,8 @@
 #ifndef EIGEN_ARRAYBASE_H
 #define EIGEN_ARRAYBASE_H
 
+namespace Eigen { 
+
 template<typename ExpressionType> class MatrixWrapper;
 
 /** \class ArrayBase
@@ -236,4 +238,6 @@ ArrayBase<Derived>::operator/=(const ArrayBase<OtherDerived>& other)
   return derived();
 }
 
+} // end namespace Eigen
+
 #endif // EIGEN_ARRAYBASE_H