MINOR: session: add a pointer to the session's origin

A session's origin is the entity that was responsible for creating
the session. It can be an applet or a connection for now.
diff --git a/src/hlua.c b/src/hlua.c
index 2934054..363c09b 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -2197,6 +2197,8 @@
 		goto out_fail_conn1;
 	appctx->ctx.hlua.socket = socket;
 	appctx->ctx.hlua.connected = 0;
+	socket->s->sess->origin = &appctx->obj_type;
+
 	LIST_INIT(&appctx->ctx.hlua.wake_on_write);
 	LIST_INIT(&appctx->ctx.hlua.wake_on_read);
 
diff --git a/src/peers.c b/src/peers.c
index df6d47a..c27fad0 100644
--- a/src/peers.c
+++ b/src/peers.c
@@ -1169,6 +1169,7 @@
 		goto out_fail_conn1;
 	appctx->st0 = PEER_SESS_ST_CONNECT;
 	appctx->ctx.peers.ptr = (void *)ps;
+	s->sess->origin = &appctx->obj_type;
 
 	si_reset(&s->si[1]);
 
diff --git a/src/stream.c b/src/stream.c
index 132e425..357e561 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -123,6 +123,7 @@
 
 	s->sess->listener = l;
 	s->sess->fe  = p;
+	s->sess->origin = &cli_conn->obj_type;
 
 	s->si[0].flags = SI_FL_NONE;
 	s->si[1].flags = SI_FL_ISBACK;