git-daemon enabled on kernel.org

After getting gitweb behind mod_cache, the load on kernel.org has gotten 
down into the tolerable range, so I have enabled git-daemon in an 
attempt to fix that :)

The URL, obviously, is git://git.kernel.org/pub/scm/...

(or, to specify a specific server, git1.kernel.org or git2.kernel.org.)

I consider this experimental so far, and if it imposes an unacceptable 
load I'll have to disable it.  It currently runs with an inetd-imposed 
limits of 10 instances per server.

	-hpa