Merge branch 'jc/capabilities'

Some capabilities were asked by fetch-pack even when upload-pack did not advertise that they are available. Fix fetch-pack not to do so. * jc/capabilities: fetch-pack: mention server version with verbose output parse_feature_request: make it easier to see feature values fetch-pack: do not ask for unadvertised capabilities do not send client agent unless server does first send-pack: fix capability-sending logic include agent identifier in capability string