Handle splitscreen lua hud lists separately

Closes #935

See merge request !1925

Invert OpenGL rollangle for papersprites to match software renderer behaviour

Closes #849

See merge request !1924

Minor interpolation fixes

Closes #900, #906, and #916

See merge request STJr/SRB2!1923

Fixes #935 by ensuring each drawlist is drawn separately while
stplyr is set correctly.

Fixes #900 pop-in animation being affected by framerate

Fixes #906

Uses the old displacement of the minecart to position the mark relative
to its destination. It's not completely correct, but it works.

Fixes #916

This reverts merge request !1920

Gamepad fixes & changes

Closes #813

See merge request !1899

Fix fox follower's flickering flindicator (fixes #819)

Closes #819

See merge request !1918

Fix use after free bug

See merge request !1867