Quantification tool

When the user closes a forecasting document, QuanTB must check if the document was changed (in a new or opened forecasting) and ask the user if he wants to save the forecasting data before closing.

1. User calls the close command to close the active forecasting;
2. QuanTB checks if forecasting document was changed.
3. If document was not changed, the document is simply closed and nothing else is done, and flow finishes here;
4. If document is changed, QuanTB display a confirmation window asking to the user "Do you want to save the forecasting data before closing the document?"
5. If the user's answer is NO, close the document and do nothing;
6. If the user's answer is YES, the system checks if it's a new file and calls the "Save as..." procedure, otherwise if it's an existing file, QuanTB calls the "Save" procedure;