Predefined actions get automatically disabled according to context

Starting with version 2.20, (or with version 2.10 when FGL_USENDIALOG=1), the dialogs will automatically disable some predefined actions if it makes no sense to trigger the action in the current context. For example, during an INPUT ARRAY, if there are no rows to remove, the predefined delete action will be disabled automatically. Similarly, the insert and append actions get disabled when the array is full (this can happen with static arrays or when using the MAXCOUNT attribute). The predefined actions will also be disabled if you overwrite them with your own ON ACTION handler.