This directory contains the same extension of `spigot` example, except
that the source files are in `src/` subdirectory.  This is a typical
arrangement when you have larger C sources.

This is to show how to write a sub `Makefile.in` under `src/`.  Other
than `Makefile.in`, all files are unchanged except that C and precompiled
Scheme sources are moved under `src/`.

See `../spigot/README.adoc` for the detailed explanation of building
extensions.
