- Further integrated tutorial.rst (Section 2 in Userguide) with links to

  supervised and unsupervised learning.
- Added a tutorial menu page to the user guide as Section 2, making the old
  Section 2 a sub-header thereof.
- Added the Scikit-learn tutorial of Gael Varoquaux to the tutorial
  menu page
  NOTE: the scikit-learn tutorial will, once fully integrated and linked up
  move down to become point 2.3 as Oliviers tutorial will be merged in
  as point 2.1
- NOTE: the scikit-learn has not been fully merged yet, just linked-to
  and added to the menu.