Add Query::page()

This method is a simpler to use version of limit + offset which also
provides some backwards compatibility with older versions + find() that
was in them.
Clean up controller a bit

Remove some magic methods + add missing properties whose warnings were
hidden by __get() and __set().

Fix a few failing tests that relied on magic methods, and skip tests
that are currently broken because model loading is incomplete.

Also fix Controller::paginate() not accepting a Table instance.
Fix error in paginatorhelper that prevented URL generation.

Fix errors in URL generation where page numbers were always broken.