Make the router object available to the URL helper.

This allows dynamic generation of URLs for routes applied to the router.
This means the URL generation is simpler, cleaner and more integrated.
Renamed a variable in the URL helper
Added Two Columns Right base page template and associated styles.
Renamed app.scss to core.scss
Each code pool can now have its own routes.php file.
Ignore everything in src/config/user, except the gitkeep file.
Updated version of mattyg/http package to v2.1.0.
Bumped the version number up to 0.5.0 and updated the readme file.