* add Regression module, from eigen1, improved, with doc and unit-test.

* fix .normalized() so that Random().normalized() works; since the return
type became complicated to write down i just let it return an actual
vector, perhaps not optimal.
* add Sparse/CMakeLists.txt. I suppose that it was intentional that it
didn't have CMakeLists, but in <=2.0 releases I'll just manually remove
Sparse.

Eigen/src/Core/Dot.h

@@ -292,10 +292,13 @@ inline typename NumTraits<typename ei_traits<Derived>::Scalar>::Real MatrixBase<
   * \sa norm(), normalize()
   */
 template<typename Derived>
-inline const typename MatrixBase<Derived>::ScalarQuotient1ReturnType
+inline const typename MatrixBase<Derived>::EvalType
 MatrixBase<Derived>::normalized() const
 {
-  return *this / norm();
+  typedef typename ei_nested<Derived>::type Nested;
+  typedef typename ei_unref<Nested>::type _Nested;
+  _Nested n(derived());
+  return n / n.norm();
 }
 
 /** Normalizes the vector, i.e. divides it by its own norm.