lua add menu callback

forum user fprockboxer asked for a way to detect long presses within the
do_menu routine this adds that functionality

result = rb.do_menu("Title",t_items, start, menu_callback)

function menu_callback(action)
    ...
    return action
end

Change-Id: I110c590095a743a57d0a7d45b24309899a4629cf
1 file changed