I have more work done on the plugin mechanism. Plugin names and their associated directories are now totally case-insensitive. They can now reside in three different locations:

      the current directory (.),
      the directory of the current file being processed,
      the plugins directory.

Also added a bunch of debug stuff and sanity tests.

And, while hacking away, I've made the pretty printer for error/warning messages even pretty by using the terminal width for formatting.

All is very cool. Release coming soon.