Sets the subject prefix. Normally empty but it can be RFC for
RFC patches, or RESEND if you are being ignored.
+Series-name: name
+ Sets the name of the series. You don't need to have a name, and
+ patman does not yet use it, but it is convenient to put the branch
+ name here to help you keep track of multiple upstreaming efforts.
+
Cover-letter:
This is the patch set title
blah blah