Pitch and roll, and slope equivalents

[Chearii]

Adds the 2.2 sprite pitch and roll variables and all relevant visual effects.

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Along with that, rotation on slopes has recieved an overhaul:

• sloperoll now has a brother: slopepitch. All visuals related to these variables are now handled in the renderers, and not the game logic.
• During saltyhops, sloperoll and slopepitch are not updated. This is mostly because the player's sprite tilting mid-hop looked strange to me.
• sloperoll and slopepitch affect 3D models now (only in midair).
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• More objects aside from players now rotate on slopes.
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• Related to the above, the Player Distortion option is now Sprite Distortion, and any relevant rotation options have also been renamed.
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• Toggleable consvar for a player's drift sparks and boost trails to rotate on slopes: cv_sparkroll
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• Addition of the P_RollPitchMobj(mobj) function, which is exposed to Lua. I cannot verify if usage in Lua is netsafe.
• pitch, roll, slopepitch, and sloperoll now all have interpolation.

Tested on 64bit on OpenGL (with models on and off), and on software. Also tested on a local netgame with a vanilla 1.6 client, with no issues discovered.

[alufolie91]

finally.... rotated bananas X)

actually wanted slope rotation for non player mobjs since quite a while c: tested it quickly and everything looks very good. this even fixes the issues looking back and splitscreen player rotation had before really nice c:

however since this changes alot of things i really want to test it thoroughly so its gonna be merged into Saturn-Next instead for now just in case