header format:
  dword: offset of main area start
  dword: number of main area entries
  dword: offset of name area start
  dword: offset of data area start

main area entry format:
  dword: offset into name area of setting name
  byte: setting name length
  byte: setting type
    0x00: string
    0x01: color
    others: reserved
  word: reserved
  qword:
    if sz string:
      dword: offset into data area of start
      dword: length of string
    if color:
      byte: red value
      byte: green value
      byte: blue value
      byte: reserved
      dword: reserved

currently used settings:
  "kbd-layout", sz string:
    the name of the scancode table for the keyboard driver to use.
    if it is <layout>, the file at sys/scantabs/<layout>.sct is loaded.
  "wm-border-color", color:
    the color to use for window borders