Kill old TMatrix and TVector code

See merge request !1821

Automatically apply flipspecial to upside-down FOF conveyor belts

See merge request !1827

Fix equation slopes overflow

Closes #757

See merge request STJr/SRB2!1830

win32: Add dpi aware manifest config

See merge request !1835

Revive the dummy interface

See merge request !1831

Allow linedef action 439 to set different back-side textures (again)

See merge request !1812

Don't require floor touch for currents in non-FOF sectors

Closes #893

See merge request !1826

Check for SF_CANBUSTWALLS, not glide&climb (resolves #892)

Closes #892

See merge request !1825

Fix reading the value of stagefailed

See merge request !1819

Don't require floor touch for currents in non-FOF sectors unless it's a horizontal currents in binary (because backwards compatibility)

Request 24-bit depth buffer from SDL

See merge request !1635

Add carry type to fans (with fixed merge conflicts)

See merge request !1809

Fix __len metamethod ignored on tables

See merge request !1328

Clean up the WAD searching code a little.

See merge request !1678

readhuditem parse fixes

Closes #887

See merge request !1816

Fix action 457 (Track object angle) not triggering the 'failure' tag

Closes #883

See merge request !1814

Fix 'exclusive' flag on plane scrollers being inverted

Closes #885

See merge request !1813

Fix UDMF FOF flags

See merge request !1802

Fix readhuditem not parsing flags correctly
Fix unknown word warning erroneously describing the HUD item as a level header

Allow objects with MF2_LINKDRAW to use their own color

See merge request STJr/SRB2!1576