fixup! phlcon_reviewstatecache: expose active review set
abdi_processrepoarglist: do one repo at a time

Make collecting results from repositories simpler by processing just one
repository at a time.

Test Plan:
$ ./precommit.sh
abdi_processrepoarglist: merge worker review cache

Improve efficiency by merging the active review list back from the
worker processes. This means we'll pre-fetch most of the reviews that
we're interested in.

Test Plan:
$ ./precommit.sh