[PATCH] Squid-to-origin SNI for ssl-bump

This patch add support for Server Name Indication (SNI) tls extension to
the Squid outgoing connections.

The SNI tls extensions allow the client to request the domain name
during SSL connection initialization and before the certificates are
exchanged. This is allow implementing virtual hosts on SSL web servers.

Some informations about SNI exist here:
    http://en.wikipedia.org/wiki/Server_Name_Indication

This is a Measurement Factory project.