* 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

test/cwiseop.cpp

@@ -59,7 +59,12 @@ template<typename MatrixType> void cwiseops(const MatrixType& m)
 
   VERIFY_IS_APPROX(               mzero,    m1-m1);
   VERIFY_IS_APPROX(               m2,       m1+m2-m1);
-  VERIFY_IS_APPROX(               mones,    m2.cwiseQuotient(m2));
+#ifdef EIGEN_VECTORIZE
+  if(NumTraits<Scalar>::HasFloatingPoint)
+#endif
+  {
+    VERIFY_IS_APPROX(               mones,    m2.cwiseQuotient(m2));
+  }
   VERIFY_IS_APPROX(               m1.cwiseProduct(m2),    m2.cwiseProduct(m1));
 
   VERIFY( m1.cwiseLessThan(m1.cwise(bind2nd(plus<Scalar>(), Scalar(1)))).all() );