- improve and comment the "BasicStuff" test.

- adjust behavior of Matrix(int,int) constructor
- s/EI_/EIGEN_/

src/Core/Difference.h

@@ -23,8 +23,8 @@
 // License. This exception does not invalidate any other reasons why a work
 // based on this file might be covered by the GNU General Public License.
 
-#ifndef EI_DIFFERENCE_H
-#define EI_DIFFERENCE_H
+#ifndef EIGEN_DIFFERENCE_H
+#define EIGEN_DIFFERENCE_H
 
 template<typename Lhs, typename Rhs> class Difference
   : public Object<typename Lhs::Scalar, Difference<Lhs, Rhs> >
@@ -48,7 +48,7 @@ template<typename Lhs, typename Rhs> class Difference
       : m_lhs(other.m_lhs), m_rhs(other.m_rhs) {}
 
     // assignments are illegal but we still want to intercept them and get clean compile errors
-    EI_INHERIT_ASSIGNMENT_OPERATORS(Difference)
+    EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Difference)
 
   private:
     const Difference& _ref() const { return *this; }
@@ -80,4 +80,4 @@ Object<Scalar, Derived>::operator-=(const Object<Scalar, OtherDerived> &other)
   return *this = *this - other;
 }
 
-#endif // EI_DIFFERENCE_H
+#endif // EIGEN_DIFFERENCE_H