* fix in IO.h, a useless copy was made because of assignment from

Derived to MatrixBase.
* the optimization of eval() for Matrix now consists in a partial
  specialization of ei_eval, which returns a reference type for Matrix.
  No overriding of eval() in Matrix anymore. Consequence: careful,
  ei_eval is no longer guaranteed to give a plain matrix type!
  For that, use ei_plain_matrix_type, or the PlainMatrixType typedef.
* so lots of changes to adapt to that everywhere. Hope this doesn't
  break (too much) MSVC compilation.
* add code examples for the new image() stuff.
* lower a bit the precision for floats in the unit tests as
  we were already doing some workarounds in inverse.cpp and we got some
  failed tests.

Eigen/src/SVD/SVD.h

@@ -538,10 +538,10 @@ bool SVD<MatrixType>::solve(const MatrixBase<OtherDerived> &b, ResultType* resul
   * \returns the SVD decomposition of \c *this
   */
 template<typename Derived>
-inline SVD<typename MatrixBase<Derived>::EvalType>
+inline SVD<typename MatrixBase<Derived>::PlainMatrixType>
 MatrixBase<Derived>::svd() const
 {
-  return SVD<typename ei_eval<Derived>::type>(derived());
+  return SVD<PlainMatrixType>(derived());
 }
 
 #endif // EIGEN_SVD_H