Move the setting of the correct headers for ESI from ESI parsing time to delivery time. 
This is in anticipation for set req.esi = off; 

Allows you to turn off esi processing for a specific request using set req.esi = off even 
if the object has been esi processed -- this is useful if you have a cache heirarchy of 
varnish machines as well as debugging. 
Only change to processing is to store a copy of the attribute value instead of 
mangling to original. Committed from Oahu.



git-svn-id: http://www.varnish-cache.org/svn/branches/2.0@4082 d4fa192b-c00b-0410-8231-f00ffab90ce4