* sets DOS locale using the same algorithm as MS' diskcopy.dll
* uses CONFIG.SYS menu to allow US vs non US selection
* only applies to WinME/MS-DOS for now (no FreeDOS)
* also renamed msdos.c -> dos.c with minor improvements
* also added missing FreeDOS credits in about dialog
* Disk Drive ID fixup for FAT32 was already available in ms-sys with option -p
* modified code to add FAT16 as well as FAT32 support as well as minor fixes
* reverts previous patch write_fat_32_br() and write_fat_16_br()