Resolve "[NEXT] moved UPnP to it's own thread"

Closes #1173

See merge request STJr/SRB2!2263

Optimize polygon sorting on batch renderer

See merge request STJr/SRB2!2253

Fix bans by remote admins corrupting banlist

See merge request STJr/SRB2!2266

Update & save unlockables when visiting a new map

Closes #1122

See merge request STJr/SRB2!2279

Fix 3D floor texture skewing

See merge request STJr/SRB2!2281

General NiGHTS Fixes

See merge request STJr/SRB2!2199

Fix segfault when setting up view frame for a removed mobj

See merge request STJr/SRB2!2270

Resolves #1122

Fix #1177

Closes #1177

See merge request STJr/SRB2!2268

Fixes for !2190

See merge request STJr/SRB2!2273

Add v.getSectorColormap and P_GetSectorLightLevelAt

See merge request STJr/SRB2!2230

Improve addon download refusal messages

See merge request STJr/SRB2!2153

Ported skincolor cache management from the secondcolor branch
Adjusted R_GetTranslationRemap to use a similar caching scheme
Made sure that if a skincolor was updated, then related translations would be rebuilt

Delete 'translations' Lua global

Moved string conversion helpers into m_misc.c
Adapted parser to check for '"'
Check if tokenizer returned NULL

Capture '"' characters
Capture ';' tokens
Implement tracking of the current line

Add can_change for console variables

See merge request STJr/SRB2!2196

ZDoom translations

See merge request STJr/SRB2!2190

Fix IPv6 bans incorrectly banning IPv4 address

See merge request STJr/SRB2!2265

This reverts commit fc1e8fb5.

Draw Character in NiGHTS Attack

See merge request STJr/SRB2!2175

add mutex locks to UPnP Client code

[OpenGL] Fix DSZ2 Wall Bruhs

See merge request STJr/SRB2!2264