The 86F handler now reads and writes .86F images correctly again;

Improved TeleDisk support;
Added support for ImageDisk (IMD) images;
Added MSR registers 186 and 570 for the Intel i686 CPU's;
Applied both mainline PCem commits.

src/disc_imd.h

@@ -0,0 +1,7 @@
+/* Copyright holders: Kiririn
+   see COPYING for more details
+*/
+void imd_init();
+void imd_load(int drive, char *fn);
+void imd_close(int drive);
+void imd_seek(int drive, int track);