redo the loadGameData API format

* Fixes #828
* Jenkins: http://jenkins.buttonweavers.com:8080/job/buttonmen-cgolubi1/291/

I'll put some comments over on #828 itself about what i did and didn't do here.  Please take a look at this; obviously, it was a pretty hefty rewrite.  I made Jenkins happy and did what hand-testing i could think of, but it's very likely i introduced bugs.