* vectorize dot product, copying code from sum.

* make the conj functor vectorizable: it is just identity in real case,
  and complex doesn't use the vectorized path anyway.
* fix bug in Block: a 3x1 block in a 4x4 matrix (all fixed-size)
  should not be vectorizable, since in fixed-size we are assuming
  the size to be a multiple of packet size. (Or would you prefer
  Vector3d to be flagged "packetaccess" even though no packet access
  is possible on vectors of that type?)
* rename:
  isOrtho for vectors ---> isOrthogonal
  isOrtho for matrices ---> isUnitary
* add normalize()
* reimplement normalized with quotient1 functor

Eigen/src/Core/util/Constants.h

@@ -143,10 +143,10 @@ enum DirectionType { Vertical, Horizontal };
 enum ProductEvaluationMode { NormalProduct, CacheFriendlyProduct, DiagonalProduct };
 
 enum {
-  NoVectorization,
   InnerVectorization,
   LinearVectorization,
-  SliceVectorization
+  SliceVectorization,
+  NoVectorization
 };
 
 enum {