WIP: Start numeric type for resources

Opening for comments on this approach. Not functional yet.
I agree that there are more subtleties in the output formatting than the input, but one of the things I detest is trying to work out just exactly how big 400000000 is. The whole point of these things was to make them human friendly. 

So here's another way to proceed: Daniel has what looks like a pretty decent design that will (I think) work: it preserves the format people enter values in.  I agree that it's fine (for now) to emit full-int values for times we don't have a specifier: that I agree we can get fancier with, later. Let's accept it, and try it out.