Merge branch 'dl/format-patch-cover-from-desc'

The branch description ("git branch --edit-description") has been used to fill the body of the cover letters by the format-patch command; this has been enhanced so that the subject can also be filled. * dl/format-patch-cover-from-desc: format-patch: teach --cover-from-description option format-patch: use enum variables format-patch: replace erroneous and condition