MINOR: lua: export applet and task handlers

The current functions are seen outside from the debugging code and are
convenient to export so that we can improve the thread dump output :

  void hlua_applet_tcp_fct(struct appctx *ctx);
  void hlua_applet_http_fct(struct appctx *ctx);
  struct task *hlua_process_task(struct task *task, void *context, unsigned short state);

Of course they are only available when USE_LUA is defined.
diff --git a/src/hlua.c b/src/hlua.c
index c76abc6..1c87daa 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -5596,7 +5596,7 @@
  * Task wrapper are longjmp safe because the only one Lua code
  * executed is the safe hlua_ctx_resume();
  */
-static struct task *hlua_process_task(struct task *task, void *context, unsigned short state)
+struct task *hlua_process_task(struct task *task, void *context, unsigned short state)
 {
 	struct hlua *hlua = context;
 	enum hlua_exec status;
@@ -6404,7 +6404,7 @@
 	return 1;
 }
 
-static void hlua_applet_tcp_fct(struct appctx *ctx)
+void hlua_applet_tcp_fct(struct appctx *ctx)
 {
 	struct stream_interface *si = ctx->owner;
 	struct stream *strm = si_strm(si);
@@ -6596,7 +6596,7 @@
 	return 1;
 }
 
-static void hlua_applet_http_fct(struct appctx *ctx)
+void hlua_applet_http_fct(struct appctx *ctx)
 {
 	struct stream_interface *si = ctx->owner;
 	struct stream *strm = si_strm(si);