patch.extract extracts just the message below HG changeset patch. So to not
parse comments above the patch, we reset the message if we find a changeset
patch as we know the commit message comes after the changeset patch data.
This is similar to the behavior of patch.extract.
The drawback of this approach, after a qref -e the comment above HG changeset
patch is gone. Without this patch the message would become part of the commit
message in the HG changset patch part.
When navigating through a patch series by qpushing and qpopping it was easy to
get lost because qpop was silent. I found myself often running qnext after qpop
to see which patch I just dropped - especially if I was about to qrm it. This
patch makes qpop more symmetric to qpush by showing which patches are
applied/"unapplied".
I think it is a good change even though it changes output by adding a new line
of output.
This extension produces quite a lot of informational messages during
its normal operation and it is hard to say which strings can be
changed and which cannot.
