TW-18 A friendly "not found" page

Adding the functionality to the Apache plugin to provide a default landing page in the case of a student mistyping their url:

e.g.
http://herpderpderpderpderp.course.training.com/ , Apache will trigger a 404 handler that will serve the landing page.

It will also show the landing page on:

http://course.training.com/
http://training.com/

The page will contain instructions on how to access the controller or for students, info on how to format their urls properly. It can also contain information on the course, like schedule, etc, and is fully customizable. Just commit to a Github repo and provide the URL! Done.