contrib/rpm: Don't exclude files that are not built

RPM still insist that they need to exist in order to be excluded.
contrib/rpm: Fix Fedora 19 build

ModemManager there is too old for Bluetooth to work.
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