busybox

- Rename getpty() to xgetpty() and adjust callers.
- Rewrite kbd_mode and setconsole
- Introduce and use console_make_active() and xopen_xwrite_close()
- honour buffer-reservation method as set by the user (dumpkmap, loadkmap)
- shrink rtcwake and some console-tools

  Saves about 270 Bytes