introduce D-Bus Configuration Service

Related to #750

Signed-off-by: Jakub Filak <jfilak@redhat.com>
testsuite: add D-Bus Configuration tests

Related to #750

Signed-off-by: Jakub Filak <jfilak@redhat.com>
spec: install D-Bus Configuration files

Closes #750

Signed-off-by: Jakub Filak <jfilak@redhat.com>