This timer only gets incremented by the main game ticker when the playsim is running.
This timer gets used for all playsim-related timing and animations so that these are decoupled from imprecisions in the global timer.
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.
* Build timer still requires initialisation due to multiple `timerSetCallback()` that still need to work.
# Conflicts:
# source/core/menu/menu.cpp
# source/games/duke/src/game.cpp
* Current setup was broken and unusable.
* Fixed interpolation issues.
* Only call `GetInput()` at frame-rate when `cl_syncinput` is 0.
* Create `oq16look_ang` and interpolate it for enhanced smoothness.
* Always reset `horizAngleAdjust` and `horizSkew` in `processinput_d()`.
* Don't pre-scale `sb_avel` in `processinput_d()` and `processinput_r()`.
* Promote `p->angvel` from short to fixed_t.
* Don't descale `sync[snum].q16horz` in `processinput_d()` and `processinput_r()`.
* Ensure `false` bool is provided to `sethorizon()` call in `processinput_d()` and `processinput_r()`.
* Reset `p->q16angvel` in `resetplayerstats()`.
The checks for game pause were totally inconsistent, so now there is a utility function that tells whether the game is supposed to run or not.
pause can also take 3 values now - 0 for no pause, 1 for pause from opening the menu or console or 2 for hitting the pause button.
