maint: Add .mailmap entries for patches claiming list authorship

maint: Add .mailmap entries for patches claiming list authorship

The list did not author any patches, but it does rewrite the
'From:' header of messages sent from any domain with restrictive
SPF policies that would otherwise prevent the message from reaching
all list recipients.  If a maintainer is not careful to undo the
list header rewrite, and the author did not include a manual
'From:' line in the body to fix the munged header, then 'git am'
happily attributes the patch to the list.  Add some mailmap
entries to correct the few that have escaped our attention; while
we also work on improving the tooling to catch the problem in
the future before a merge is even made.

Also improve the comments occurring in the file, including line
length improvements.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>