Enhancements to views tutorial

Correct a mistake (memory backend reference), links to 2 demos
(Slickgrid, Graph), change graph demo to match the code in the page and
to use date grouping and set type on dataset accordingly.
Clarifications on not needing recline.js/sep. files at the same time.
Merge pull request #453 from mattfullerton/master

Enhancements to views tutorial