Fix slope contrast

See merge request STJr/SRB2!2585

Further improve sleep accuracy on UNIX systems

Closes #1210

See merge request STJr/SRB2!2583

Update outdated __HAIKU__ directives

See merge request STJr/SRB2!2569

Fix CMake not finding OpenMPT on Haiku

See merge request STJr/SRB2!2570

Fix BootMap not having any effect when loaded from the addon menu

See merge request !2529

Add CVar for changing room ID

See merge request !2487

Model animation duration fixes

See merge request !2498

Add actual multiplayer automap support

See merge request !2488

Refactor TTY input handling

See merge request !2451

Fix issues with custom pause menu binds

See merge request !2305

Replace gluBuild2DMipmaps with GL_GENERATE_MIPMAPS

See merge request !2287

Extra resolutions

See merge request !1795

Convert waddir to an absolute path

Closes #1310

See merge request !2538

Fix being unable to use CTRL keyboard shortcuts on menu input fields (resolves #1338)

Closes #1338

See merge request !2580

Fix buffer overflow when reading string from R_TextureNameForNum into Lua

Closes #1341

See merge request !2582

Put HTTP downloading on a background thread

See merge request STJr/SRB2!2322

Fix segfault due to leftover ztargetfocus when switching maps

Closes #1333

See merge request !2573

Fix plane offsets overflow in the software renderer

Closes #1322 and #1227

See merge request STJr/SRB2!2575

Correctly force Sonic in the tutorial (resolves #1331)

Closes #1331

See merge request STJr/SRB2!2571

Fix segfault when switching perfstats screen before sampling is done

See merge request STJr/SRB2!2576