rpm: reload dbus in wicked-service post-install (bnc#897775)

We install dbus security policies for wicked service -- ensure
we tell dbus to (re)load them after installation / uninstall.
rpm: dbus policies as noreplace config (bnc#897775)

We still mark the policies as config to keep backups, but
replace them on upgrade to ensure they match new daemons.
man: added startmode hotplug and use-nanny (bnc#896403)
Merge pull request #438 from mtomaschewski/dbus-reload
Merge pull request #439 from mtomaschewski/dbus-replace-config
Merge pull request #440 from mtomaschewski/ifcfg-hotplug