Remove misplaced SetShader call in CompileShaders (Fixes #402)

Closes #402

See merge request !1423

Use double precision in R_StoreWallRange sloped seg culling calculations (Fixes #434)

Closes #434

See merge request !1424

Print a backtrace when SRB2 crashes in a Unix-like environment.

See merge request STJr/SRB2!1288

Fixes culling issues in CEZ2 skybox

Check if GME_VERSION is defined.

See merge request !1372

Fix CA_BOUNCE height when flipped (Fixes #428)

Closes #428

See merge request !1373

Disable pausing during score screens in marathon mode

See merge request !1416

Fix translation colormap cache rebuilding using the old translation enumerations (fixes #443, #449, #459)

Closes #443, #449, and #459

See merge request STJr/SRB2!1421

Fix thing scale mismatch in R_DrawVisSprite. (Fixes #458)

Closes #458

See merge request STJr/SRB2!1420

Revert "Merge branch 'player-speed' into 'next'"

Closes #466 and #471

See merge request STJr/SRB2!1418

This was causing a buffer underwrite too. Lovely.

Fix "implicit declaration of function 'DEH_TableCheck'" warning

See merge request STJr/SRB2!1419

Nice UDB config there, SRB2.

See merge request !1354

Dependency files

See merge request STJr/SRB2!1407

This reverts merge request !1309

Make DEBUGMODE=1 builds (finally) compile, run and work in netgames

See merge request !1405

This makes it print nothing to stdout.

Also fixed some irregularities.

This removes Makefile.depends. Instead, '.d' files are included from the 'dep'
directory. This speeds up building because dependencies for every file don't
need to be regenerated if only one changes.

As a bonus, dependencies also won't be generated if only clean type targets
are going to be run. Also added a 'distclean' target, which cleans both
objects and dependency files.

MOBJCONSISTANCY checks confined to gamestate GS_LEVEL. DEBUGMODE
no longer implicitly enables them, making it netgame-compatible.

A few minor tweaks before 2.2.9

See merge request !1403