2002.06.04 ~15  FI decoys

Weapons Factory has a feature called "decoys".  These are solid objects
that are visually similar to the owner, and little else -- no health, no
armor, no weapons, no controls.  The idea is basically to momentarily
deceive enemies, usually to get them to waste a shot or expose their
position(s).

Perusing the source code, I extracted decoyness from CopyToBodyQue(), which
replicates the player's body as a corpse that lies around.  The player
entity is always within 0 to 63, and other game entities are 64 to 1023.
Since the player and their past-life corpse can coexist, CopyToBodyQue
copies all properties of the player (0-63) into a game entity (64-1024) so
that two separate (identical) bodies can coexist, but the player entity is
always under control by client (client 2 always controls player 2, etc.).

Basically I duplicated CopyToBodyQue() and changed some of the copied
properties so that the replica is standing (or at least not lying down).
The problem is that I can't seem to get the model to be solid.  Splash
damage can destroy the decoy, but direct damages (bullets, rail, gauntlet)
pass right through it (including players!).  One hint is that
client-prediction wants to clip at the decoy, but the server says to go
ahead and pass through.  I'm thinking I should attack bg_pmove.c, but I'll
still poke around anyway.