GEOMESA-297 Ingest Command: Allow for Ingesting subset of data columns

It is for after Geomesa release 1.0.
This is confusing.  Why not just explicitly list the columns and column ranges?  Couldn't the examples below be represented by:

1. "1,4-6,10"
2. "1-2,4,6-8,10-12"
3. "3,6-8,10-12,15-17"