Rewritten 808x CPU emulation core based on reenigne's XTCE, VisiOn, SnatchIt, and 8088 MPH now work correctly;

Fixed PC speaker sound volume in PIT mode 0;
A few CPU emulation clean-ups;
Hard disk controller changing redone in a less messy way;
Re-added the long-missing key send delay handling to the XT keyboard handler;
Fixed a bug that was causing SLiRP not to work when compiled with MingW/GCC 7.3.0-2 or newer;
Some serial mouse and port fixes;
A lot of changes to printer emulation, mostly based on DOSBox-X;
Printer PNG writer now uses statically linked libpng;
Added support for the HxC MFM floppy image format and upped 86F format version to 2.12;
Ported various things from PCem and some from VARCem;
Added the S3 86c801/805 emulation (patch from TheCollector1995);
Fixed and renamed the EGA monitor options;
Better synchronized the 808x to the PIT and the CGA;
Fixed the CGA wait state calculation;
Cleaned up some things in mem.c;
Fixed some things in the floppy emulation to make VisiOn get the correct errors from the copy protection disk;
Fixed several renderer-related bugs, including the SDL2 renderer's failure to take screenshots;
The Jenkins builds are now compiled with MingW/GCC 7.4.0-1 and include all the required DLL's.

src/floppy/fdd_mfm.h

@@ -0,0 +1,26 @@
+/*
+ * 86Box	A hypervisor and IBM PC system emulator that specializes in
+ *		running old operating systems and software designed for IBM
+ *		PC systems and compatibles from 1981 through fairly recent
+ *		system designs based on the PCI bus.
+ *
+ *		This file is part of the 86Box distribution.
+ *
+ *		Implementation of the HxC MFM image format.
+ *
+ * Version:	@(#)fdd_mfm.h	1.0.0	2018/11/12
+ *
+ * Authors:	Miran Grca, <mgrca8@gmail.com>
+ *
+ *		Copyright 2018 Miran Grca.
+ */
+#ifndef EMU_FLOPPY_MFM_H
+# define EMU_FLOPPY_MFM_H
+
+
+extern void	mfm_seek(int drive, int track);
+extern void	mfm_load(int drive, wchar_t *fn);
+extern void	mfm_close(int drive);
+
+
+#endif	/*EMU_FLOPPY_MFM_H*/