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

Closes #1173

See merge request !2263

Optimize polygon sorting on batch renderer

See merge request !2253

Fix bans by remote admins corrupting banlist

See merge request !2266

Update & save unlockables when visiting a new map

Closes #1122

See merge request !2279

Fix 3D floor texture skewing

See merge request !2281

General NiGHTS Fixes

See merge request !2199

Fix segfault when setting up view frame for a removed mobj

See merge request !2270

Resolves #1122

Fix #1177

Closes #1177

See merge request !2268

Fixes for !2190

See merge request !2273

Add v.getSectorColormap and P_GetSectorLightLevelAt

See merge request !2230

Improve addon download refusal messages

See merge request !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 !2196

ZDoom translations

See merge request !2190

Fix IPv6 bans incorrectly banning IPv4 address

See merge request !2265

This reverts commit fc1e8fb5.

Draw Character in NiGHTS Attack

See merge request !2175