Add independent cross-section lines to 2018 settings.

With the cross-section lines running alongside the 'normal' lines, the inputs to the cross-section lines must be 'namespaced' as they can be different.

What I haven't namespaced are the Common cuts. With respect to the 5 TeV running last year, the only difference is the inclusion of a ghost probability cut of < 0.4. This is a pretty safe (and sensible) addition IMO, we used it in the 13 TeV measurements and the data-MC difference can be included in the tracking efficiency correction studies.

I realise I haven't added a (new) Omega_c line here, but it's something to consider if we think it'd be useful (although we're well passed the deadline).

/cc @spradlin @mrwillia @adzyuba

RM: I sneaked in a fix for LBHLT-364