* Blood had this right. It makes sense that the horizon be based around as it's easier to work with.
* Removed all associated game math to deduct default horizon of 100 when doing weapon zvel etc, meaning actual horizon can just be used.
* Re-did return to center function to work on the already converted pitch. Return speed should be 1:1 with previous code.
* For Blood/SW, exposes `SB_LOOK_LEFT`/`SB_LOOK_RIGHT` to games, hooking up `q16look_ang` and `q16rotscrnang` within.
* For SW, use Duke & Blood's return to center function and remove `PF_TURN_180` bit.
* For RR, replace a few misused bits with some bools inside of `player_struct`.
* Since bulk of functionality is sourced from Duke (30Hz), apply proper scaling so SW speed matches (40Hz).
* Need SW's input helpers available for Blood but therefore also need an angle delta function that does not seem to exist in Blood.
* Realise that gamecontrol.h/cpp might not be the most appropriate place, but it's a shared location and these will go into binaryangle.h when its utilisation can be more realised.
* Because SW's logic was reversed, in that param #1 was the new angle and param #2 was the current, all calls have been reversed.
* By happenstance, also fixes an issue with multiple 180° turns in quick succession.
* Provide read-only/const results from `CONTROL_GetInput()` so games can't change received input.
* Change non-descript `info` to `hidInput` (Human Interface Device).
* Remove a few unused prototypes.
* use static_assert directly. Raze is C++17, no need for that macro shit.
* removed CONSTEXPR - I seriously fail to see the use here, many of the functions marked as CONSTEXPR cannot possibly even be constant evaluated so the declaration makes no sense. Removed most of these and replaced the valid ones with the official constexpr keyword.
* got rid of EDUKE_PREDICT_FALSE - this makes zero sense in script parsing code, at best it will save a few microseconds. Clean code wins.
* replaced Blrintf with xs_CRoundToInt. Shitty name is shitty name, even if derived from POSIX.
* replaced Bstr*casecmp with str*icmp. As these get defined in the CMake project based on actual compiler checks they are preferable here.
* removed lots of other stuff that is not needed with a minimum compiler requirement of C++17.
The remaining excpetions are the "give" CCMD and any level change action.
Unfortunately the implementation of most cheats is not multiplayer safe so right now it'd only be useful for demo recording (assuming that worked to begin with... ;))
* Remove bool `PedanticMode`.
* Transition appropriate lines to `cl_syncinput`.
* Remove inlines added purely only to maintain DOS demo compatibility.
* Fix a few pedantic Q16.16 >> Int >> Q16.16 conversions.
* Remove fix16.h/cpp and utilise library from m_fixed.h.
* Extend m_fixed.h with two inline functions for int to/from float operations.
* Replace fix16_floor operations with those from xs_Float.h
* Replace multiple Q16.16 conversions from 0 to just be 0.
* Replaced all found in-game bit-shifts and multiplications/divisions with inline functions from m_fixed.h
* Replaced many casts of FRACUNIT as double in SW's panel.cpp as it is converted to double by way of type promotion.
* Fixed missed precision fixes in SW's panel.cpp where some types weren't declared correctly.
* Replaced 100+ `Cos()/Sin() >> 16` operations for Blood with inline functions `CosScale16()/SinScale16()`.
In particular this means to remove the option to disable widescreen aspect ratios. The way this was handled makes no sense with the current render backend.
The aspect ratio code will have to be redone entirely to properly obey the backend's settings.
