Split views into layout/header/footer/content.

Add Layout controller and layout/header/footer templates.
Remove header/footer from existing templates.
Make User controller extend Layout.
Copy some layout handling to OAuth controller
Add SYSPATH check to all views
Better error messages

Wrap errors in a layout template with header and footer.
Drastically cut down the 404 error
Leaving the default error message pretty much as is, to style later.
Better error handling on user login/register

Catch login errors and pass them to the form template
Pass registration error to the form template.
Populate form with values used on previous submission.