This allows clients to ask for tarballs with:
git tar-tree --remote=git://server/repo refname
By default, the upload-tar service is not enabled. To enable
it server-wide, the server can be started with:
git-daemon --enable=upload-tar
This service is by default overridable per repostiory, so
alternatively, a repository can define "daemon.uploadtar = true"
to enable it.
Signed-off-by: Junio C Hamano <junkio@cox.net>