The old words said "not yet run in QEMU" and "each machine keeps its own
peasants".  Both are false now, and false words in a README are a sin.

- How to play together: the include lines, host presses 2, guest
  presses 3 and types the host's IP, the keys of both games, what
  "The port 2017 is taken" and "No one answered" mean.
- Two Temples on one computer.  Two QEMU user-mode NATs, both Temples
  are 10.0.2.15, the Mac is 10.0.2.2.  The host's UDP 2017 goes to the
  Mac, the guest knocks on 10.0.2.2.  Linux lines too.
- Limits: no seal, two brothers not three, same window size, and the
  Titanium sky that freezes even alone in this build -- not NetGame's
  sin, being hunted.

run_mac.sh: GAME_PORT forwards UDP 2017 of the Temple to the Mac,
GAME_BIND=0.0.0.0 opens it to the LAN.  Not set, nothing is forwarded:
a door you did not ask for is a door the CIA walks through.