The directory structure of /var/lib/PACKAGE is re-encoded in the
postinst scripts; the rationale being that even if the names of the
directories could be shipped with the package, the information of how
to chown all those directories needs to be explicit in the postinst
script anyway, which can then just as well create them.

Checks to be done after changing the package:

* `cme check dpkg`
* `lintian *.changes`
* `piuparts -d stable *.deb`
