fixed a bug of not checking the return value of wcrtomb properly in qse_wcrtomb().

fixed a bug of passing a wrong buffer to qse_wcrtomb() in qse_wcsntombsn().
enhanced qse_tio_writembsn() and qse_tio_writewcsn()

qse/lib/cmn/str-fnmat.c

@@ -199,6 +199,7 @@ static int __mbsxnfnmat (
 
 					if (pl >= 9) 
 					{
+						/* TODO: binary search or something more efficient ? */
 						if (qse_mbszcmp(pp, QSE_MT("[:upper:]"), 9) == 0) 
 						{
 							matched = QSE_ISMUPPER(sc);