Body responses are no longer being automatically parsed for json
Don't use differential saving on data contexts if they've never been saved
Better logic when saving data contexts

1) Mark the parent document dirty the first time we save a data context
(which replaces the data context with an id reference in the main
document)
2) Make sure we update the shadow copy after the first time we save a
data context, so that the next save will have the correct differences.
3) Make sure any time a data context fails to save, we mark it for
saving again next time.