seconds instead of cleaning it in every new connection received.
We are using it here, and the performance is much better now.

Submmitted by:	Rafael Umann <rafael.umann@terra.com.br>

Closes ticket #235



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@2646 d4fa192b-c00b-0410-8231-f00ffab90ce4