Turn the lua sector lines hack into a macro

See merge request !1187

Set cvars directly from Lua

See merge request !1205

Add multithreading option for CMake

See merge request STJr/SRB2!1204

Only invoke the Lua API for mobj hooks that need it

See merge request STJr/SRB2!1209

Do not let previous wait commands affect COM_BufInsertText

See merge request !1207

Fix G_GhostTicker crashing trying to read netvars as ghost data

See merge request !1203

NPO2 span function optimization

See merge request STJr/SRB2!1201

Kick clients that fail to catch up with server gamelogic

See merge request STJr/SRB2!1208

CV_SetValue merged with CV_Set (same with CV_StealthSetValue and CV_StealthSet).

Also fixed possible issue with incorrectly reading the demo pointer due to the wrong type being passed to sizeof in G_ConsGhostTic

Model fallback

See merge request STJr/SRB2!1167

Bustable Wall and Floor flags.

See merge request !1163

Performance stats

See merge request !1186

R_FindPlane optimization

See merge request STJr/SRB2!1199

Apply step up/down to opposite plane too

See merge request STJr/SRB2!1192

Lua polyobjects

Closes #19

See merge request STJr/SRB2!1140

Make record attack's quick retry more consistent.

Closes #80

See merge request STJr/SRB2!1193

Fix OpenGL GIF recording crashing with gif_localcolortable disabled

See merge request STJr/SRB2!1196