Previously we always used SO_LINGER to make sure that all queued data
got transmitted, no matter under which circumstances we closed the
client connection.

Change this so that SO_LINGER is only activated for orderly connection
closure (ie: "Connection: close" from client or error handling), in
all other cases (usually the client connecting on us, abandon any data
queued for transmission.

This _may_ reduce the tendency of worker threads to get hung up on
network failures a little bit.



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@4046 d4fa192b-c00b-0410-8231-f00ffab90ce4