* Big rework of Assign.h:

** Much better organization
** Fix a few bugs
** Add the ability to unroll only the inner loop
** Add an unrolled path to the Like1D vectorization. Not well tested.
** Add placeholder for sliced vectorization. Unimplemented.

* Rework of corrected_flags:
** improve rules determining vectorizability
** for vectors, the storage-order is indifferent, so we tweak it
   to allow vectorization of row-vectors.

* fix compilation in benchmark, and a warning in Transpose.

Eigen/src/Core/Matrix.h

@@ -89,7 +89,7 @@ struct ei_traits<Matrix<_Scalar, _Rows, _Cols, _MaxRows, _MaxCols, _Flags> >
     MaxColsAtCompileTime = _MaxCols,
     Flags = ei_corrected_matrix_flags<
                 _Scalar,
-                ei_size_at_compile_time<_MaxRows,_MaxCols>::ret,
+                _Rows, _Cols, _MaxRows, _MaxCols,
                 _Flags
             >::ret,
     CoeffReadCost = NumTraits<Scalar>::ReadCost