policy-rc.d script with declarative syntax

 Debian policy states that packages providing system services need to
 start those services by default, and that the starting of the service
 should be done by way of the /usr/sbin/invoke-rc.d script. This script
 will execute a program /usr/sbin/policy-rc.d if it exists, allowing the
 local system administrator to override behaviour if wanted by creating
 a policy script accordin to the interface specified and installing it
 under the correct name. This interface is however somewhat problematic,
 as explained in https://bugs.debian.org/911290.
 .
 This package attempts to provide a solution by shipping a policy-rc.d
 script that allows system administrators to define policies in a
 declarative way through one or more configuration files, rather than
 providing one script that may be overwritten.