Restore view.c weaponmodel fudging

[leilei-]

I know fitz ripped it out long ago. When you've got scr_sbaralpha 1 with the classic refdef restored, the gun position to compensate for the visibility loss of the weapon model is not. Double-barreled shotgun suffers from this the worst.

Here's a pic of just the shotgun. Qspasm left, Engoo right, everything lines up visually except for the weapon

(also seen in the picture is an inconsistency with overbright models, as software renderer clamped some of the overbright down. 0.5 setting to match that behavior too maybe?)

[ericwa]

This is the fudging that fitzquake removed:
https://github.com/id-Software/Quake/blob/bf4ac424ce754894ac8f1dae6a3981954bc9852d/WinQuake/view.c#L944

The annoying thing is, the amount of gun visible in winquake changes a lot with different resolutions (because the status bar is staying at 1:1 pixels I guess..):

320x240:

640x480:

but weird at 800x600 (gun sticks out too far imo)

I'm not sure what we should do but yeah I agree on this, I prefer the winquake @ 320x240 positon

[leilei-]

Seeing more of the gun with smaller bars with the nudge is standard behavior too. 320x480 in the dos version made this rather eregious

[ericwa]

Added a cvar for restoring the winquake positioning, r_viewmodel_quake (same cvar as MarkV) in ab77972