Tidy some functional test macros

Tried to remove some tests from the macros and replace some ``view_test`` ones with simple ``test`` ones.  The general approach was to assert on the object graph in ``assigns()`` instead of ``assert_select`` on the rendered view.

Didn't really manage to cut off that many, so I'm not sure there's much of an improvement speed wise. :(  The next approach is to look for helpers, form builder and view objects that can be extracted and tested indepenedently to cover the remaining ``view_test``s.