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

Eigen/Sparse

@@ -1,8 +1,6 @@
 #ifndef EIGEN_SPARSE_MODULE_H
 #define EIGEN_SPARSE_MODULE_H
 
-namespace Eigen {
-
 /** \defgroup Sparse_modules Sparse modules
   *
   * Meta-module including all related modules:
@@ -16,8 +14,6 @@ namespace Eigen {
   * \endcode
   */
 
-} // namespace Eigen
-
 #include "SparseCore"
 #include "OrderingMethods"
 #include "SparseCholesky"