Fixups for #99 and #112: the version raised for the object message's
shader permutation, NETCODE.md brought up to date, a networked glass
break's sound placed where it broke, a frame scratch pool that runs out
logged once, and the new comments marked as the port's.
Fixups for #102, #103 and #105-#107: the version raised for the glass,
scenery, cutscene cluster and revert messages, NETCODE.md brought up to
date, co-op's followers' object lists freed as soon as they are used, and
extra enemies that find no free ground placed on the rings they used before
rather than left out (at 32x a quarter of them were), with the places found
taken not tried again for the rest of the squad, and the way to a place
looked along level.
Hosting a co-op level from the Map screen (CO-OP CAMPAIGN, a level and its
difficulty, then Server Setup) makes a network game on the campaign map
with no game engine, which is what co-op is. Only the host runs the
scripts and the AI; port/linux/game/network_coop.c sends clients what the
scripts do (cutscenes, camera, fades, HUD, sounds, devices, named objects,
animations), and network_actors.c drives the host's AI units on every
machine. Players spawn beside each other, respawn beside a safe teammate,
and spectate while dead or waiting. Skipping a cutscene is a vote.
Players can join a game in progress at any time.