mq: support "qimport --existing --name renametothis thatexistingpatch" Before this change, the command would abort with a not too clear "patch renametothis does not exist" error. This change makes: qimport --existing --name renametothis thatexistingpatch equivalent to: qimport --existing thatexistingpatch; qrename thatexistingpatch renametothis