The registrations are now done against app classes, not app instances.

The tests in test_view_directive and test_path_directive work now, but
a lot more work cleaning up the tests is to be done.

This is a work in progress -- more changes are to be expected.
newest version of pytest
Remove lots of tests now irrelevant, but repair the one that tests
the caching of lookup.
Fix the test_extend tests.
Intermediate checkin. Lots of tests start to work again, but lots
more needs to be done.
Lots more fixes to tests and code to make class-based apps work.
Trying to make the function action stuff work reveals issues with
registration. The App object seems to be picked up twice during testing.
Thankfully, setup_testing turns out not to be needed after all,
as setup() already scans the App object into existence.
Rename '.morepath' to '.registry'.
Rename _mounted to just mounted, as it's on the registry.
Rename some bits of registry to 'registry' instead of app.
Improve API docs.
Update docs to reflect the new apps are classes era.
Explain breaking changes.
pyflakes.
Create a proper directive directive.
Break long line.
Streamline behavior of resolve_model.
Remark optimization.
Expose 'mounted' attribute on app.