use the sphinxcontrib.autoprogram extension to pull the argparse parsers from each script so that the documentation auto-syncs with changes in each script's option

Not ready for merging.

Procedure:
1) rename script to use underscores instead of dashes
2) make argparse building to a function
3) move documentation from doc/scripts.txt to the tool's argparse. Make a pre-formatted epilog if needed using any ReStructuredText you want to.

Preview: http://athyra.ged.msu.edu/~mcrusoe/build/sphinx/html/scripts.html

@ctb @luizirber @camillescott : thoughts?