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

diff --cc builtin/receive-pack.c
Simple merge

diff --cc cache.h
Simple merge

diff --cc connect.c
Simple merge