Merge branch 'al/ref-filter-merged-and-no-merged'

"git for-each-ref" and friends that list refs used to allow only one --merged or --no-merged to filter them; they learned to take combination of both kind of filtering. * al/ref-filter-merged-and-no-merged: Doc: prefer more specific file name ref-filter: make internal reachable-filter API more precise ref-filter: allow merged and no-merged filters Doc: cover multiple contains/no-contains filters t3201: test multiple branch filter combinations