Add default root welcome page

This commit adds the generating of a welcome controller and updating of
the routes to make this the root page.

So now when you run the rahebo script and run the app for the first time
you won't see the generic rails welcome screen.
Add title updating in application layout

This commit updates rahebo so that it will inject the project name into
the application layout's title.

I've also updated the layout itself so that the title gets capitalized.