log tags for a connection, and clear the collected log data on seeing the open
tag. This resolves an issue with log data where varnishncsa would consider a
set of data as bogus because of extra data in the log belonging to the previous
connection.

Support case 164.


git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@5162 d4fa192b-c00b-0410-8231-f00ffab90ce4