- To change the app version:
   - Edit storylen.cabal:  Version: XXX
   - Edit src/StoryLen/Opts.hs, usageText near the bottom of footer
   - darcs rec these changes as "Changed version to XXX"
   - darcs tag "storylen vXXXa"
     Use a, b, c as attempts for version XXX

   I'd like to make a script in util/ to automate this.
   After such a script has been made, may want to put developer notes on using it in doc/dev/<somefile>