Fix up Lua command/cvar safety

See merge request STJr/SRB2!1943

Fix buffer overflow in setcontrol with 2 arguments

See merge request STJr/SRB2!1954

Fix use-after-free when Metal Sonic charges energy balls

See merge request STJr/SRB2!1956

Fix segfault when destroying wall spike while it moves

See merge request STJr/SRB2!1959

Fix crash during debug when escaping pterabyte

See merge request STJr/SRB2!1960

Fix R_SkinUsable crashes in (some) custom addons

Closes #994

See merge request STJr/SRB2!1962

Fix custom ambient sound mobjs not working

See merge request STJr/SRB2!1961

Fix flag mixup in P_GetOldFOFFlags()

Closes #995

See merge request STJr/SRB2!1958

Add basic rate limitation for Lua file access

See merge request STJr/SRB2!1947

Add flag to action 433 to force MFE_VERTICALFLIP

See merge request STJr/SRB2!1948

Bot adjustments

See merge request STJr/SRB2!1951

These commands be run from Lua:

- add
- addfile
- addfolder
- archivetest
- ban
- banip
- causecfail
- cecho
- cechoduration
- cechoflags
- changeteam
- changeteam2
- charability
- charspeed
- cheats
- clearbans
- clearscores
- connect
- countmobjs
- csay
- demote
- devmode
- displayplayer
- downloads
- drop
- droprate
- dumplua
- echo
- exitgame
- exitlevel
- gametype
- getallemeralds
- getplayernum
- god
- gravflip
- help
- hurtme
- isgamemodified
- jumptoaxis
- kick
- listwad
- login
- manual
- map
- mapmd5
- masterserver_update
- memdump
- memfree
- mod_details
- motd
- noclip
- nodes
- notarget
- numnodes
- numthinkers
- objectplace
- password
- pause
- ping
- playintro
- promote
- quit
- reloadbans
- resendgamestate
- resetcamera
- resetemeralds
- restartaudio
- retry
- rteleport
- runsoc
- savecheckpoint
- say
- sayteam
- sayto
- scale
- screenshot
- serverchangeteam
- setcontinues
- setlives
- setrings
- showbanlist
- showmap
- showscores
- showtime
- skynum
- startmovie
- stopdemo
- stopmovie
- suicide
- teleport
- toggle
- togglemodified
- toggletwod
- tunes
- version
- vid_info
- vid_modelist
- vid_nummodes
- weather

Renames COM_SAFE to COM_LUA.

These cvars can be modified by Lua.

- advancemap
- allowexitlevel
- allowjoin
- allowmlook
- allowseenames
- allowteamchange
- autobalance
- basenumlaps
- cam2_adjust
- cam2_centertoggle
- cam2_curdist
- cam2_curheight
- cam2_dist
- cam2_height
- cam2_lockaimassist
- cam2_lockedinput
- cam2_orbit
- cam2_rotate
- cam2_rotspeed
- cam2_shiftfacingchar
- cam2_simpledist
- cam2_simpleheight
- cam2_speed
- cam2_still
- cam2_turnfacingability
- cam2_turnfacingchar
- cam2_turnfacinginput
- cam2_turnfacingspindash
- cam2_turnmultiplier
- cam_adjust
- cam_centertoggle
- cam_curdist
- cam_curheight
- cam_dist
- cam_height
- cam_lockaimassist
- cam_lockedinput
- cam_orbit
- cam_rotate
- cam_rotspeed
- cam_shiftfacingchar
- cam_simpledist
- cam_simpleheight
- cam_speed
- cam_still
- cam_turnfacingability
- cam_turnfacingchar
- cam_turnfacinginput
- cam_turnfacingspindash
- cam_turnmultiplier
- color
- color2
- competitionboxes
- cooplives
- coopstarposts
- countdowntime
- exitmove
- flagtime
- forceskin
- friendlyfire
- gravity
- hidetime
- inttime
- itemfinder
- killingdead
- matchboxes
- maxplayers
- mute
- numlaps
- overtime
- pausepermission
- playersforexit
- pointlimit
- powerstones
- respawndelay
- respawnitem
- respawnitemtime
- restrictskinchange
- ringslinger
- runscripts
- scrambleonchange
- seenames
- servername
- showhud
- showinputjoy
- skin
- skin2
- specialrings
- startinglives
- tailspickup
- teamscramble
- timelimit
- touchtag
- tv_1up
- tv_bombshield
- tv_eggman
- tv_forceshield
- tv_invincibility
- tv_jumpshield
- tv_recycler
- tv_ringshield
- tv_superring
- tv_supersneaker
- tv_teleporter
- tv_watershield

Fixes com_flags being discarded after the first command in
a chain (semicolon list).

Disable floor splat slope interpolation

See merge request STJr/SRB2!1934

Fix software vsync

See merge request STJr/SRB2!1940

Fix Explosion Ring explosion interpolation

See merge request STJr/SRB2!1941