- general bug:  J command on line with trailing spaces and following
   line with leading spaces adds extra space
- general bug:  (1) r command on empty line adds character there and
   (2) fails to display it until redraw
- general bug:  C command on a tab causes rest of line to be pulled in
   (bug or feature?  perhaps latter)
- general bug:  ^F command doesn't allow to go to last line of file
   (nice for short redraws)
- general bug:  ZZ:n not allowed
- general bug:  backspace across newlines allowed in insert mode
- general bug:  ^U, ^D don't (necessarily) move cursor


OS/2 bugs:

- set lines=xx:  want to use VioSetMode to do it (and if not supported,
   signal error [beep or whatever; don't change lines]); also restore
   to original size at end (should be able to do VioSetMode with _init
   params)
- need "real" pipes
- need detection of FAT filesystem and truncation to 8.3
- change vio_init and vio_restore stuff to work from resume_curses and
   suspend_curses (so can change video mode and still continue editing
   in new mode)--currently called from main() and endwin()
- rewrite display code to use VioGetPhysBuf() and VioShowBuf() (and "direct
   memory" writes)  [can have speed AND colors :-) ]
