* complete the change norm2->squaredNorm in PartialRedux

* somehow the NICE_RANDOM stuff wasn't being used anymore and
  tests were sometimes failing again. Fixed by #including Eigen/Array
  instead of cherry-picking just Random.h.
* little fixes in the unaligned assert page

doc/snippets/PartialRedux_squaredNorm.cpp

@@ -0,0 +1,3 @@
+Matrix3d m = Matrix3d::Random();
+cout << "Here is the matrix m:" << endl << m << endl;
+cout << "Here is the square norm of each row:" << endl << m.rowwise().squaredNorm() << endl;