* added mbr_rufus.h to ms-sys, and MBR selection to UI * also simplified int 13 override, fixing potential breakage on concurrent ints
* I'm looking at you, Dell Optiplex! * also fix boot in case no secondary bootable drive exists * also adds a readme
* Adds an MBR to prompt the use about USB or HDD boot * If USB boot is not selected, an INT13h override is added to make the second bootable drive think it is first (0x81 -> 0x80) * USB drive BIOS index is left unmodified