Fix timedemo in OpenGL mode

See merge request KartKrew/Kart-Public!209

Remove ESLOPE POLYOBJECTS POLYOBJECTS_PLANES #ifdefs (backport srb2 2.2)

See merge request KartKrew/Kart-Public!204

Fix replay recording memory leak

See merge request KartKrew/Kart-Public!208

2.2's random client port

See merge request KartKrew/Kart-Public!201

Instantaneous lookback camera (v2 backport)

See merge request KartKrew/Kart-Public!203

GME cleanup and fixes

See merge request KartKrew/Kart-Public!202

Just some stuff backported from SRB2 2.2, well mostly

get_zlib_error function to reduce code duplication

Return false if it fails to load the VGZ lump

Reduce redundant calls to gme_set_equalizer

Fix sometimes loading a VGZ crashing the game

If you ever need to, you can change the client port number.

(cherry picked from commit 843d9b9f)

Using strcpy is stupid because we don't know how long the argument would be.
There's no need for a buffer anyway.

(cherry picked from commit 4e321012)

(cherry picked from commit f584b61c)

Fix NOCURL compiling

See merge request KartKrew/Kart-Public!197

Let servers send httpsource without curl

See merge request KartKrew/Kart-Public!196

[OSX] Fix "SIGILL: illegal instruction" on macOS Catalina

See merge request KartKrew/Kart-Public!194

on OSX, strncpy may copy to overlapping (protected) memory. this
sometimes happens when loading WAD files.

This patch eliminates these problems for me

(cherry picked from commit be14b8a564a89a5afb84ac19f1586f3db7f68367)

Make the HTTP Master Server official

See merge request KartKrew/Kart-Public!193

Bump MAXNETNODES to 127

See merge request KartKrew/Kart-Public!192

Clarify addon-related messages

See merge request KartKrew/Kart-Public!190

Fix memory leak in W_ReadLumpHeaderPwad

See merge request KartKrew/Kart-Public!182

Fix user agent for HTTP downloads being set as SRB2Kart/v1.1.2

See merge request KartKrew/Kart-Public!185

Ogl colormap fix third attempt

See merge request KartKrew/Kart-Public!184

clientside ack fix

See merge request KartKrew/Kart-Public!186

Stops the client from using reliable packets before joining a server
Clients can time out during addon loading
sending reliable packets before then can cause out of order acks
This causes joinbug, chatbug, and chatspam, as well as
general server instability due to unnecesary packetspam