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
b3b2ddced2