Upgrade path: 6.x-1.x to 6.x-2.x

I've been working this week on 6.x-2.x. This new version depends on ctools, and adds the ability for other modules to add A/B test win contions as plugins. In particular, I'm adding better support for A/B tests of donations forms provided by the fundraiser module in the Springboard package.

This is mostly done and tested, but I still need to write the update hook to convert existing win conditions to use the new plugins.