TODO

   1 vt emulation
   2 ------------
   3
   4 * screen erased with background color ## capname:bce
   5 * back tab                            ## capname:cbt ## seq:CSI Z
   6 * ...
   7
   8 code & interface
   9 ----------------
  10
  11 * clean selection code
  12 * use the real x11 clipboard
  13 * clean terminfo entry
  14 * utf8
  15 * ...