make sure all existing $c->something configuration options are documented
All $c->something configuration options used in the source code should be documented both in the wiki (http://davical.dhits.nl/index.php/Configuration and particularly http://davical.dhits.nl/index.php/Configuration/settings) as well as in the example config at config/example-config.php).
At the same time, options that have been removed should no longer be mentioned / clearly marked as obsolete (e.g. code_debian, code_pkgver).