Merge branch 'ds/bundle-uri'

Preliminary code refactoring around transport and bundle code. * ds/bundle-uri: bundle.h: make "fd" version of read_bundle_header() public remote: allow relative_url() to return an absolute url remote: move relative_url() http: make http_get_file() external fetch-pack: move --keep=* option filling to a function fetch-pack: add a deref_without_lazy_fetch_extended() dir API: add a generalized path_match_flags() function connect.c: refactor sending of agent & object-format