Checkpoint initial work on reclaiming from inner notin operand.
Tweak test timing to avoid spurious failures.

Still a fundamentally non-deterministic hack, of course.
Checkpoint work on reclaiming outer (negative) input to notin.
Optimize RSE slightly.

Avoid creating redundant rules to copy into key range collection.
Improve tests for reclaiming from negative notin input.
Fix bugs in RSE for negative ("outer") notin inputs.

Given "X.notin(Y); X.notin(Z);" we can only reclaim Y, Z values when the X value
is reclaimed (which in turn requires matches in both Y and Z).