NGI_pipeline working version

It is still under testing but it should be pretty stable: @mario please review it carefully
This is a good way to start out with processing at the highest levels. We'll need to refactor this sometime soon to deal with sample- or project-level analyses (e.g. Variant Calling). I'm thinking that maybe this for-sample-for-libprep-for-fcid thing might be better moved to the individual engine modules, e.g. piper_ngi, bcbio_ngi and so on.