Only call P_CheckSurvivors() in tag gametypes

See merge request STJr/SRB2!740

# Conflicts:
#	src/g_game.c

Put the (pull request repo owner) branch and commit in Appveyor EXE names

See merge request !725

Credit Tatsuru

See merge request STJr/SRB2!728

Fix fire shield being removed under lava

See merge request STJr/SRB2!729

Fix garbage fade on Sonic's ass in OpenGL

See merge request !715

Let clients rejoin the server without losing their status

See merge request STJr/SRB2!722

Don't set controls to keys of array bounds

See merge request !723

Rename R_IsPointInSubsector to R_PointInSubsectorOrNull/Nil

See merge request STJr/SRB2!719

MUSICDEF cleanup, fixes, and VERSION directive to opt into new format

See merge request STJr/SRB2!708

Fix "cam2_turnmultiplier" being unused in "next"

See merge request STJr/SRB2!713

Fix "cam2_turnmultiplier"

See merge request !711

Fix P_AddLevelFlatRuntime again

See merge request !717

Fix mouse in controls setup menu

See merge request !706

This lets the host manually remove a body if they want,
without polluting the chat with redundant messages.

srb2win-jameds-appveyor-exename-b1d931d4.exe

srb2win-jameds:appveyor-exename-b1d931d4.exe

srb2win-master-a6d49eaa.exe

srb2win-master-a6d49eaa.exe

Disconnected players do not become IT at round start.

If all non-ITs are disconnected, the round ends.

If all ITs are disconnected, one of the non-ITs
becomes IT, or the round ends if in Hide & Seek.

Shout-out to TAG's config that somehow had
`setcontrol2 "custom3" "KEY931926528"`, cuasing the game to crash only in
Splitscreen.

The old name made it really easy to accidentally read
R_IsPointInSubsector as R_PointInSubsector, and anyway it
didn't even make sense...

# Conflicts:
#	src/g_game.c
#	src/p_setup.c