* Rename TICQUEUE to BACKUPTICS.
* Add CLIENTBACKUPTICS to limit the time gap players can send tics in at once
* This likely means freezes are more possible, and this variable could be raised later, but prevents some potential duplication in the extrapolerated tic.
- ZDEBUG2 is now ZDEBUG ... although admittedly, it doesn't seem that useful, it just enables some CONS_Debug's ... but now there's a convenient way to enable them now I suppose
- Mostly just means the I_Errors give __FILE__ and __LINE__.
- Also enables a "memdump" command that just prints a bunch of zone memory info.
I don't think any of this should be guarded, so I went ahead and did this.
* Set via a fourth digit in the upper midtexture for transparent FOFs
* For example - #2551 is additive solid, #1282 is subtractive half...
* The original method of setting the upper midtexture to #900 or 901 still works, since I'm not out to break existing maps.
* Software: Remove the horrible `else if` ladder for FOF translucency. Algorithms, baby!
* OpenGL: Move to using `HWR_GetBlendModeFlag` in more places, for more long-term extensible support for multiple blendmodes.
Literally identical to Encore remapping, but *only applied when Encore mode is OFF*. Long-requested by Oni, and allows you to reuse textures and skies from other stages without having to duplicate them in different colours.
It was changed during v2 indev to operate off textures supplied rather than offsets. Unfortunately, she didn't bank on the 2.2 merge making it so that only linedefs of specific types would generate the necessary `->text` string from their texture fields. This branch corrects that issue, along with a bonus null-avoidance in P_SetupLevelSky just in case someone messes up the source linedef.
Instead of figuring out where it should be every tick while it's visible, store where it'll be at the start of the map.
Also moved finish line beam into a new file, k_race.c/h, for any Race-specific code.
A few unused variables for sprint map support later too
