Updated readme.md for user configured styles.
Started transitioning to a PHP generated CSS file.

- Check app/views/css.blade.php.
- Route /css/main.css is being used instead of public/css/main.css, which was
just renamed to public/css/_main.css. It'll remain there, for now.
Updated tasks on readme.md.
New filter 'canEditPost'.

This route filter checks if the current logged in user can edit a post. If
he's a supervisor, then he can, but if he's not, then he only can if he's
the author of the post. This route filter performs these checkings.
Added a background-image.