AmiXcom 0.5.5 - keyboard fix

AmiXcom 0.5.5 — keyboard fix

• Keyboard works. Text entry typed the same character no matter which key was
  pressed (usually r): the raw-keycode lookup table scan was miscompiled by the
  cross-gcc at -O1 — a search for one key returned another key's entry. The lookup
  is now a direct 128-entry map, pinned to -O0. Typing, shift and all bound keys
  behave normally.
• "PORT MADE BY GRZEGORZ KORYCKI" credit on the title screen (also in the
  refreshed 0.5.0 archive).

Everything else as in 0.5.0 (see its notes: save ~7x, load ~4x, globe 3D ~10x).
No X-COM game data included — copy your own UFO/TFTD files into data/UFO / data/TFTD.