contrib/rpm: Fix Fedora 19 build

Too old to have recent enough ModemManager.
contrib/rpm: Do not count only the first parent

After an octopus merge, the first parent is not guarranteed to contain the
commit the reference pointed to previously.
Merge remote-tracking branches 'lr/lr-unmanaged-slaves', 'lr/lr-ipv6-tokens', 'lr/lr-ap', 'lr/lr-rdisc-mtu' and 'lr/lr-rpm-build' into integration