Fixed handling of DMF IMG images;

Fixed 3.5" 2ED XDF structure;
Applied mainline PCem big recompiler speedup (up to 20% seen) commit;
Added support for floppy drive swapping with the Winbond W3877F Super I/O chip.

src/fdc.h

@@ -31,6 +31,7 @@ void fdc_update_densel_force(int densel_force);
 void fdc_update_drvrate(int drive, int drvrate);
 void fdc_update_drv2en(int drv2en);
 
+int fdc_get_perp();
 int fdc_get_format_n();
 int fdc_is_mfm();
 double fdc_get_hut();