don't need this anymore, we have a new way of doing routes
Moved some stuff around in the core.php file.

Getting prepped to remove custom error handling, because the routes.php file handles it now. For a short time we'll leave in the old stuff.
Getting rid of the extra core stuff we don't need in new sites. You can still overwrite, but don't need the same thing written twice.
Created a new way to handle alias slugs.

The custom error handling is no longer needed. Yeah.

Now when you create or edit an alias it writes the routes.php file for the site, and that will handle the custom slugs.
The great part is that there is no more duplicate content, nor do you need to rewrite any html links.  They all update automagically.