Make D-Bus policy dir a compile time option
By request of Jaro (@svetlemodry) for Arch:
Todo list information:
Name: D-Bus policy in /usr/share/dbus-1/system.d instead of
/etc/dbus-1/system.d
Creator: Bruno Pagani
Description:
The former is the default one for packaging, the second should be left empty
for user overriding.