This is mostly functional, but requiring a bit of work to work for a
production environment. I'm mostly looking for feedback and possibly
some useful patches if anyone feels inclined.
a) Shouldn't one install the Engines plugin first?
The order of installation doesn't matter.
b) I would highly recommend producing a complete and detail example of how
to use your engine. Just a thought.
I'm getting to it.
c) What work is required to make this production ready?
1. Better test coverage.
2. Fixtures that don't use real people's information (that's why
there's a fixture missing from SVN)
3. More useful methods on the PaypalSubscription class.