Forwards a request
toward a proxy server specified in gatewayURL
if the request matches the condition specified in connMap,
that is, the request is in a protocol listed in protoList and
for servers listed in dstHostList and
from clients in srcHostList.
If connMap is omitted, any request are forwarded to the
gatewayURL unconditionally.
If an authentication information is given as "user:pass@"
prefixed to gwhost, it is used on the authentication phase
after the connection with the gwhost.
FORWARD is a generalized notation of ROUTE and
the following two notations are equivalent.
If multiple FORWARD parameters are specified, they are tried in the order
of the definition.
If multiple routes to the destination server are available,
specified with a mixture of FORWARD and other parameters
(MASTER, PROXY, SOCKS or SSLTUNNEL),
the route defined by FORWARD is tried in precedence defined by "proxy" or
"master" in CONNECT.
Example: a gateway for HTTP clients to a HTTPS server reachable via SSLtunnel with authentication