* Struct made up of binangle class units.
* Create signed clone of binangle for use with look_ang and rotscrnang.
* Append currently outgoing function names with `2` at the end to avoid conflict.
* Started with the most complicated game first.
* Struct made up of fixedhoriz class units.
* Append currently outgoing function names with `2` at the end to avoid conflict.
* 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.
* Duke/RR: Fix `SB_CENTERVIEW` not clearing while `cl_syncinput 1`.
* Duke/RR: Remove superfluous call to `apply_seasick()`.
* RR: Change two calls from `playerSetAngle()` to `playerAddAngle()` Updated version of `playerSetAngle()` doesn't stop setting angle until target is reached, a bit too strict for this and compromised vehicle turning.
* `applylook()`: Remove dead flag. Was only used with Duke, no other game called the function when dead anyway. Since the input helpers are processed outside of `applylook()` now this is not needed.
* `applylook()`: Extend function with a bit of commentary.
* 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).
* For Duke/SW, we continually apply `SB_CENTERVIEW` only if it was previously a toggled action, similar to Blood.
* For SW, we remove two SW-specific bits (`PF_LOCK_HORIZ` and `PF_LOOKING`) that are no longer needed.
* For Duke, we remove `return_to_center` and just use the `SB_CENTERVIEW` action bit as required.
* For `sethorizon()`, feature set and adjustment speeds are an averaged out accumulation across Duke/SW:
** GameTicRate is factored in for adjustment decisions to provide consistency for SW being the faster game.
** Adjustment amounts are half way between Duke/SW.
