Two big features that are only barely related in the same guide. Seems
bad.
I did not check references to these guides yet, so some links may need
to be updated.
Change the default test locations to avoid confusion around the common
testing terms "unit" and "functional".
Add new rake tasks for the new locations, while maintaining backwards
compatibility with the old rake tasks.
New testing locations are as follows:
app/models -> test/models (was test/units)
app/helpers -> test/helpers (was test/units/helpers)
app/controllers -> test/controllers (was test/functional)
app/mailers -> test/mailers (was test/functional)