Load and sets specs

Wrote some new specs for wagn/loader and card/sets.  I want to do some more of that before we merge this, but I also wanted to make it visible as I work on it.  I think it will be key to getting the proper split in the wagn gem work as well.  I think I'll move to wagn.org cards for that discussion.

I'm thinking also that only core mods should be with the main gem, and standard should be part of a second gem.  More for the cards discussion.