. function to convert Linux errno to DOS errno.
. convert read/write etc.. routines to return 'correct' errcodes.
. real memory alloc/dealloc/realloc functions.
. add an exec routine that does what boot_dos does, but correctly..
. Add more of the BIOS area variables.
. fixup everything to be more modular (why?, I like modular .... .).
. modify int21_names.h to use printf-like format strings and actually tell parameters and results.
. blocking on repetitive BIOS keypressed? calls
. fix drive allocation information
. Fix directory lookups to root dir
. Fix dos2unix function to parse a unix pathname as well as DOS ones
. Find out why LIST gets FPE errors when trying to read /proc/self/ or near