mod mossage_query_results() to work with field-limited ES results

If you tell ElasticSearch you only want certain fields back it
puts them in ['field'] instead of ['_source'].  Of COURSE it would
do that!
limit fields in ES list results, control result set size

- Only get id, title, description (and basename, label) for list
  views.  Otherwise it's just way too much data.
- Return a small result set by default.
- Specify unlimited result set size in list views.

Note: We are not using ElasticSearch paging. We are returning the
entire result set each time, and paging in Django.