MINOR: lua/signals: Remove Lua part from signals.

The signals system embedded in Lua can be tranformed in general purpose
signals code. To reach this goal, this path removes the Lua part of the
signals.

This is an easy job, because Lua is useles with signal. I change just two
prototypes.
diff --git a/src/hlua.c b/src/hlua.c
index 69db580..2621ba6 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -303,27 +303,27 @@
  * events like TCP I/O or sleep functions. This funcion allocate
  * memory for the signal.
  */
-static int hlua_com_new(struct hlua *lua, struct list *link)
+static struct hlua_com *hlua_com_new(struct list *purge, struct list *event, struct task *wakeup)
 {
 	struct hlua_com *com = pool_alloc2(pool2_hlua_com);
 	if (!com)
-		return 0;
-	LIST_ADDQ(&lua->com, &com->purge_me);
-	LIST_ADDQ(link, &com->wake_me);
-	com->task = lua->task;
-	return 1;
+		return NULL;
+	LIST_ADDQ(purge, &com->purge_me);
+	LIST_ADDQ(event, &com->wake_me);
+	com->task = wakeup;
+	return com;
 }
 
 /* This function purge all the pending signals when the LUA execution
  * is finished. This prevent than a coprocess try to wake a deleted
  * task. This function remove the memory associated to the signal.
  */
-static void hlua_com_purge(struct hlua *lua)
+static void hlua_com_purge(struct list *purge)
 {
 	struct hlua_com *com, *back;
 
 	/* Delete all pending communication signals. */
-	list_for_each_entry_safe(com, back, &lua->com, purge_me) {
+	list_for_each_entry_safe(com, back, purge, purge_me) {
 		LIST_DEL(&com->purge_me);
 		LIST_DEL(&com->wake_me);
 		pool_free2(pool2_hlua_com, com);
@@ -878,7 +878,7 @@
 		return;
 
 	/* Purge all the pending signals. */
-	hlua_com_purge(lua);
+	hlua_com_purge(&lua->com);
 
 	luaL_unref(lua->T, LUA_REGISTRYINDEX, lua->Mref);
 	luaL_unref(gL.T, LUA_REGISTRYINDEX, lua->Tref);
@@ -1151,20 +1151,20 @@
 		break;
 
 	case HLUA_E_ERRMSG:
-		hlua_com_purge(lua);
+		hlua_com_purge(&lua->com);
 		hlua_ctx_renew(lua, 1);
 		HLUA_CLR_RUN(lua);
 		break;
 
 	case HLUA_E_ERR:
 		HLUA_CLR_RUN(lua);
-		hlua_com_purge(lua);
+		hlua_com_purge(&lua->com);
 		hlua_ctx_renew(lua, 0);
 		break;
 
 	case HLUA_E_OK:
 		HLUA_CLR_RUN(lua);
-		hlua_com_purge(lua);
+		hlua_com_purge(&lua->com);
 		break;
 	}
 
@@ -1772,7 +1772,7 @@
 connection_empty:
 
 	appctx = objt_appctx(socket->s->si[0].end);
-	if (!hlua_com_new(hlua, &appctx->ctx.hlua_cosocket.wake_on_read))
+	if (!hlua_com_new(&hlua->com, &appctx->ctx.hlua_cosocket.wake_on_read, hlua->task))
 		WILL_LJMP(luaL_error(L, "out of memory"));
 	WILL_LJMP(hlua_yieldk(L, 0, 0, hlua_socket_receive_yield, TICK_ETERNITY, 0));
 	return 0;
@@ -1935,7 +1935,7 @@
 
 hlua_socket_write_yield_return:
 	appctx = objt_appctx(socket->s->si[0].end);
-	if (!hlua_com_new(hlua, &appctx->ctx.hlua_cosocket.wake_on_write))
+	if (!hlua_com_new(&hlua->com, &appctx->ctx.hlua_cosocket.wake_on_write, hlua->task))
 		WILL_LJMP(luaL_error(L, "out of memory"));
 	WILL_LJMP(hlua_yieldk(L, 0, 0, hlua_socket_write_yield, TICK_ETERNITY, 0));
 	return 0;
@@ -2157,7 +2157,7 @@
 		return 1;
 	}
 
-	if (!hlua_com_new(hlua, &appctx->ctx.hlua_cosocket.wake_on_write))
+	if (!hlua_com_new(&hlua->com, &appctx->ctx.hlua_cosocket.wake_on_write, hlua->task))
 		WILL_LJMP(luaL_error(L, "out of memory error"));
 	WILL_LJMP(hlua_yieldk(L, 0, 0, hlua_socket_connect_yield, TICK_ETERNITY, 0));
 	return 0;
@@ -2224,7 +2224,7 @@
 
 	hlua->flags |= HLUA_MUST_GC;
 
-	if (!hlua_com_new(hlua, &appctx->ctx.hlua_cosocket.wake_on_write))
+	if (!hlua_com_new(&hlua->com, &appctx->ctx.hlua_cosocket.wake_on_write, hlua->task))
 		WILL_LJMP(luaL_error(L, "out of memory"));
 	WILL_LJMP(hlua_yieldk(L, 0, 0, hlua_socket_connect_yield, TICK_ETERNITY, 0));