Squashed commit of the following:

commit 2c3b7f2f859f15c08f856a2d58806d86d0020990
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Wed Aug 31 16:36:18 2011 +0200

    Prove that keys are passed to libnetworkcache.

commit c380b1ea414c28478d5c2049752b6dcedb0c808f
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Wed Aug 31 15:42:05 2011 +0200

    Support shacache and dir SSL based auth.