Make sure that
        set obj.ttl = 0s
means that the object is not hit again by actually using "-1" instead.

This works around the rounding error which otherwise causes the object
to be inside TTL for up to one second - epsilon.



git-svn-id: http://www.varnish-cache.org/svn/branches/2.0@3552 d4fa192b-c00b-0410-8231-f00ffab90ce4