Tutorial for template driven site and helpers

Based off the links that were showing up on the otherwise empty page, a simple tutorial on how one might start on building up a site using templates and views.

Also includes a port of the [Helper tutorial from v2 of the docs](http://docs.kohanaphp.com/general/helpers) as well as merging in [some information from Stack Overflow](http://stackoverflow.com/questions/5647786/creating-helper-in-kohana-3-1).

Forgot to drop in the ref to #4527 in the actual commit messages - http://dev.kohanaframework.org/issues/4527