Fixed the floppy file type filters string so that its length no longer exceeds 512 bytes;

The UMC UM8669F's reset function now make sure the FDC pointer does not get lost, should fix the segmentation fault on reset;
The Winbond W83877F's reset function now zeroes the registers before setting the default values.

src/sio_um8669f.c

@@ -237,6 +237,8 @@ uint8_t um8669f_read(uint16_t port, void *p)
 
 void um8669f_reset(void)
 {
+	fdc_t *temp_fdc = um8669f_global.fdc;
+
 	fdc_reset(um8669f_global.fdc);
 
 	serial_remove(1);
@@ -252,6 +254,8 @@ void um8669f_reset(void)
         
         memset(&um8669f_global, 0, sizeof(um8669f_t));
 
+	um8669f_global.fdc = temp_fdc;
+
         um8669f_global.locked = 1;
 
 	io_removehandler(0x0279, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, &um8669f_global);