eagerly free resources for query tasks

- previously completed tasks did not free their resources until the
entire query was complete. This could could lead to dead-lock-like
behavior between or within a query under certain distributions.

- not an issue that came up, but an extra safeguard for lease
accounting for errors during option activation

- a few logging/ doc improvements

- still need to investigate unusual/ unexpected option distribution
that (somewhat luckily) provoked this issue. Multiple options from
the same host seems incorrect