Don't sleep w/ fpscap 0 and vsync enabled

See merge request !294

fix portal interp view positioning and camera reset

Closes #14 and #12

See merge request !293

Various fixes for 1.6

Closes #17, #15, and #11

See merge request !292

Update gfx.kart hash

CONS_Printf calls CON_Drawer during startup, thread
collision stuff.

Fixes some wild behavior when a lot of hole punching
requests are coming in.

This reverts commit 5ec44ba3, reversing
changes made to 4c5d69b7.

Doesn't prevent it from happening later if the rules weren't successfully fetched, though.

Notably caused by a difference in behaviour between Software and GL that was already resynchronised in the 2.2 codebase.

Seems to be a regression in internal too. Requires more analysis on behaviour in the 2.2 engine, but essential for maintaining compatibility in 2.1 (such as with Opulence wobbly carpet).

- `cv_masterserver` - Replaces a hack checking for the original SRB2 MS addres every time, and additionally catches those who tested an early version of the http MS.
- `cv_usegamma` - This was previously WAY too easy to accidentially change. This way, a user who has had this accidentially happen will automatically return to baseline.

I originally wrote a ridiculous attempt at reimplementing the existing value rollaround. For one reason or another, that sidesteps net transmission. Let's just avoid all those hacks and limit our influence to changing the maximum allowed range.

Doesn't affect the conditions that allow entry -- just avoids pointlessly resetting the map if it occurs during the period where literally nothing can happen.

v1.4 prep

See merge request KartKrew/Kart!631