I've separated this into two separate PRs, one for docs and one for tests/implementation.

I have not yet implemented the logic for the ability to configure the TZPATH at compile time because I'm not quite sure how to start on that. How are other compile-time options implemented? Do I need to do something special to handle both Windows and POSIX systems? Is there already a configuration file somewhere that I should use for this? Adding Thomas to the nosy list because he's the only one listed for "autoconf/makefiles" – don't know if that extends to the Windows build as well.