bundle-uri: serve bundle.* keys from config
Implement the "bundle-uri" protocol v2 capability by populating the
key=value packet lines from the local Git config. The list of bundles is
provided from the keys beginning with "bundle.".
In the future, we may want to filter this list to be more specific to
the exact known keys that the server intends to share, but for
flexibility at the moment we will assume that the config values are
well-formed.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>