[MEDIUM] New option http_proxy

Hello,

You will find attached an updated release of previously submitted patch.
It polish some part and extend ACL engine to match IP and PORT parsed in
HTTP request. (and take care of comments made by Willy ! ;))

Best regards,
Alexandre
diff --git a/src/backend.c b/src/backend.c
index 91027e8..a8676b3 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -936,6 +936,10 @@
 				return SRV_STATUS_INTERNAL;
 			}
 		}
+		else if (s->be->options & PR_O_HTTP_PROXY) {
+			if (!s->srv_addr.sin_addr.s_addr)
+				return SRV_STATUS_NOSRV;
+		}
 		else if (!*(int *)&s->be->dispatch_addr.sin_addr &&
 			 !(s->fe->options & PR_O_TRANSP)) {
 			return SRV_STATUS_NOSRV;
@@ -999,6 +1003,10 @@
 			return SRV_STATUS_INTERNAL;
 		}
 	}
+	else if (s->be->options & PR_O_HTTP_PROXY) {
+		/* If HTTP PROXY option is set, then server is already assigned
+		 * during incoming client request parsing. */
+	}
 	else {
 		/* no server and no LB algorithm ! */
 		return SRV_STATUS_INTERNAL;