Finish pulling out regression outputs

[jeanconn]

I got started pulling out the regression outputs in https://github.com/sot/starcheck_regress , but never got around to finishing. I think this just needs some setup in the starcheck Makefile and some notes/docs for process.

I think that should be re-baselined at starcheck 13 (or now 13.2) and all of the old regression outputs should be tossed.