Remove manual AutoPage registering in test

That register call is redundant, as the auto_page => 1 setting causes it
to register itself already
AutoPage should not serve layout files

This patch removes the AutoPage handler's ability to serve files undes
$view_dir/layouts. In order to allow manual routes with '/layouts/' as
regex the AutoPage handler passes the response in order to allow other
routes to serve the request.
Use layout_dir attribute, check engine first:

layout_dir was provided after this was written, but merged before,
so it could be used here. By using a configuration, if the user sets
their layout directory somewhere else, it will still work.

We also check the template first to exit early. There's no point to
check it with the template if the template is not available.
reflect change
Merge branch 'fix/autopage_not_serve_layouts'