amend: turn currentdate into tri-state bool so config option can be negated Otherwise, rewrite.update-timestap couldn't be overridden by --no-currentdate. FWIW, which do we like? --no-currentdate vs --no-current-date. If the latter is preferred, maybe we can add "graft --current-date" and deprecate "--currentdate".

discovery: improve partial discovery documentation The older documentation could be improved.

discovery: add a simple `addinfo` method The method can directly process a sample result. This makes the main code simpler to follow.

discovery: move missing tracking inside the partialdiscovery object This is the final set that we need to track to have a fully up to date information within the object.