add test for geometry with eigen2_ prefixes. fix that stuff.

Eigen/src/Eigen2Support/Geometry/Rotation2D.h

@@ -22,8 +22,8 @@
 // License and a copy of the GNU General Public License along with
 // Eigen. If not, see <http://www.gnu.org/licenses/>.
 
-#ifndef EIGEN_ROTATION2D_H
-#define EIGEN_ROTATION2D_H
+// no include guard, we'll include this twice from All.h from Eigen2Support, and it's internal anyway
+
 
 /** \geometry_module \ingroup Geometry_Module
   *
@@ -155,5 +155,3 @@ Rotation2D<Scalar>::toRotationMatrix(void) const
   Scalar cosA = ei_cos(m_angle);
   return (Matrix2() << cosA, -sinA, sinA, cosA).finished();
 }
-
-#endif // EIGEN_ROTATION2D_H