* Add 'summaryonly' parameter.

* Implement summaryonly.

* More changes on proving a summary with no data:

1. Migrate to apiserver 0.9.6 which means replacing the int value with
  { Total: int, Namespace: <empty map> }
This is a requirement going from apiserver 0.9.5 to 0.9.6

2. Avoid making a query for data when all the items will be dropped -- we
still need to make a COUNT(*) query for the UI to do pagination, but
don't need to decode blobs from the database tables and the other work.

* Finish the rebase manually.

In particular this is because the 54935 work moved some code from
sqlgenerator into summary_fields