tests/test-parseindex2.py.out

bookmarks: explicitly track identical bookmarks

bookmarks.compare() previously lumped identical bookmarks in the
"invalid" bucket. This patch adds a "same" bucket.

An 8-tuple for holding this state is pretty gnarly. The return value
should probably be converted into a class to increase readability. But
that is beyond the scope of a patch intended to be a late arrival to
stable.

done