Major commit, cleaning a lot of old stuff.

IBM.H is gone, video stuff re-organized. Keyboard stuff reorganized.
Machines that have their own video, mouse and/or keyboard now have all this in their machine file.
Fixed and other cleanups here and there.

src/machine/m_xt.c

@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <wchar.h>
+#include "../86box.h"
+#include "../nmi.h"
+#include "../pit.h"
+#include "../mem.h"
+#include "../device.h"
+#include "../game/gameport.h"
+#include "../keyboard.h"
+#include "machine.h"
+
+
+void
+machine_xt_init(machine_t *model)
+{
+    machine_common_init(model);
+
+    pit_set_out_func(&pit, 1, pit_refresh_timer_xt);
+
+    device_add(&keyboard_xt_device);
+    nmi_init();
+    if (joystick_type != 7)
+	device_add(&gameport_device);
+}