* What about if the per-section inheritance references settings in the
  DEFAULT section of the inherited file?... perhaps a flag to indicate
  how to handle this?...

* There should be a command-line tool that converts iniherit-enabled
  INI files to flat "standard" INI files.

* Implement `write`... this could be done by tracking which config
  items are "dirty", and only saving those to the base INI...
