lua Add scrollable stack traceback WIP

lua currently splashes a stack traceback on error
for deep tracebacks and especially on devices with smaller screens
this leaves out a lot of vital information

in the past I have resorted to splitting the traceback string or
even saving the return to a file

This patch provides a scrollable buffer with rudimentary text reflow
to allow you to read the whole traceback string

Upon traceback if you press nothing the screen will display for 5 seconds
If you press OK or CANCEL it will quit immediately
PREV/NEXT scrolls the list on button press timeout is disabled

lua now provides rb.splash_scroller(timeout, str)

example script provided too

Change-Id: Idbc8ce0c514196f0fae48c43aeaea8b60d6da1a5

apps/plugins/lua/rocklib.c

@@ -287,6 +287,14 @@ RB_WRAP(do_menu)
     return 1;
 }
 
+RB_WRAP(splash_scroller)
+{
+    int timeout = luaL_checkint(L, 1);
+    const char *str = luaL_checkstring(L, 2);
+    int action = splash_scroller(timeout, str); /*rockaux.c*/
+    lua_pushinteger(L, action);
+    return 1;
+}
 
 /* DEVICE AUDIO / PLAYLIST CONTROL */
 
@@ -948,6 +956,7 @@ static const luaL_Reg rocklib[] =
     RB_FUNC(kbd_input),
     RB_FUNC(gui_syncyesno_run),
     RB_FUNC(do_menu),
+    RB_FUNC(splash_scroller),
 
     /* DEVICE AUDIO / SOUND / PLAYLIST CONTROL */
     RB_FUNC(audio),