SERVER-37721 optionally includes in-progress index builds in listIndexes results, but the returned index specs do not reflect the difference between in-progress and ready indexes. We must be able to tell the difference, for the purposes expressed in SERVER-37721.

This is as simple as exposing

and

in the index specs that listIndexes returns.

Note: if I recall right, we currently interpret the absence of the 'ready' field in the persisted index catalog entry as either true or false – we don't persist it all the time. I think the higher level parsing code interprets it correctly for the in-memory index catalog at least: extend the interpretation to listIndexes results.