MINOR: server: add a list of already used idle connections

There's a difference with the other idle conns in that these new
ones have already been used and may be reused by other streams.
diff --git a/include/types/server.h b/include/types/server.h
index f72ca0c..411ea4b 100644
--- a/include/types/server.h
+++ b/include/types/server.h
@@ -167,6 +167,7 @@
 	struct list pendconns;			/* pending connections */
 	struct list actconns;			/* active connections */
 	struct list priv_conns;			/* private idle connections attached to stream interfaces */
+	struct list idle_conns;			/* sharable idle connections attached or not to a stream interface */
 	struct task *warmup;                    /* the task dedicated to the warmup when slowstart is set */
 
 	struct conn_src conn_src;               /* connection source settings */
diff --git a/src/hlua.c b/src/hlua.c
index 08831ab..df3904f 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -5061,6 +5061,7 @@
 	LIST_INIT(&socket_tcp.actconns);
 	LIST_INIT(&socket_tcp.pendconns);
 	LIST_INIT(&socket_tcp.priv_conns);
+	LIST_INIT(&socket_tcp.idle_conns);
 	socket_tcp.state = SRV_ST_RUNNING; /* early server setup */
 	socket_tcp.last_change = 0;
 	socket_tcp.id = "LUA-TCP-CONN";
@@ -5105,6 +5106,7 @@
 	LIST_INIT(&socket_ssl.actconns);
 	LIST_INIT(&socket_ssl.pendconns);
 	LIST_INIT(&socket_ssl.priv_conns);
+	LIST_INIT(&socket_ssl.idle_conns);
 	socket_ssl.state = SRV_ST_RUNNING; /* early server setup */
 	socket_ssl.last_change = 0;
 	socket_ssl.id = "LUA-SSL-CONN";
diff --git a/src/server.c b/src/server.c
index 44f0dc3..e33f686 100644
--- a/src/server.c
+++ b/src/server.c
@@ -887,6 +887,7 @@
 			LIST_INIT(&newsrv->actconns);
 			LIST_INIT(&newsrv->pendconns);
 			LIST_INIT(&newsrv->priv_conns);
+			LIST_INIT(&newsrv->idle_conns);
 			do_check = 0;
 			do_agent = 0;
 			newsrv->flags = 0;