OpenGL slope FOF lighting fix
This fixes some issues with sloped FOFs that affect lighting in OpenGL (as in, those that cast a shadow or have a colormap). Particularly, they can do strange things to any wall textures adjacent to them, as we've noticed ourselves in levels for 2.2. =P
See merge request !194
Fixes with respect to sector special touching and slopes
Some important stuff.
* SF_TRIGGERSPECIAL_TOUCH now actually works. Previously, it abandoned the loop early if ANY bounding sector didn't have that sector flag, which it likely didn't - only checking one extra sector's worth of FOFs. Also, the teleport handling there is more robust, and actually bails out if you teleport, instead of just awkwardly continuing through the loop.
* SF_TRIGGERSPECIAL_TOUCH now works for each time thinkers, too.
* Fixed a bug with being able to go under lava because P_CheckSolidLava doesn't take slopes into account.
* Also, P_CanRunOnWater supports slopes now too.
* Quicksand supports slopes and reverse gravity now.
* Space Countdown supports slopes now.
Also, an experiment behind a #define which currently isn't turned on:
* UNDER A #define, "SECTORSPECIALSAFTERTHINK", WHICH IS CURRENTLY TURNED OFF, BUT I WILL WANT TO TURN ON IN INTERNAL: Moved sector touch handling to P_PlayerAfterThinker (from P_PlayerThinker before movement). Allows for being able to trigger moving slope sectors that are going down, most specifically lava (didn't matter in RVZS in 2.1 because you could clip through the sides and go underneath the lava, causing damage - a sloped testwad version of that prevented going underneath.) Also fixes one-frame standing on deathpits before you die. Basically means sector triggers effectively happen one tic earlier, since it's after movement.
See merge request !131
Polyobject seg render fix
This fixes both Software and OpenGL renderers so that polyobject segs aren't drawn if the game is drawing the actual subsectors they're from (outside the main level, where the polyobject walls were pre-spawn). They should only appear as part of the polyobject itself in-level.
This means a few glitches with polyobjects are probably fixed: for instance in Software mode, polyobject walls sometimes appear through level boundaries (and make everything above/below vanish, turning into HOM or skybox), if the BSP rendering code happens to find one of the subsectors said segs came from outside the level. I don't think anything similar happens in OpenGL, though I'm sure some unwanted typecasting is happening as a result of attempting to draw the segs. (And it fixes a crash in 2.2 anyway.)
See merge request !195
Ping-related code fix
Somehow, the part of the netcode for calculating the players' pings in a netgame frequently gets the concepts of nodes and players mixed up, which is probably not a good thing. This branch of course fixes those slipups.
I originally based this branch on master to be merged to it (since it only fixed issues on the host's side), but after finding another issue with clients receiving PT_PING from the server, I decided to make this a merge to next instead.
See merge request !193
Ld414 invalid sound fix
This fixes Linedef type 414 crashing the game if an invalid sound number was supplied to it (this can happen if you, say, scrambled THZ2's textures *cough*), whether or not the "Repeat Midtexture" flag is checked.
See merge request !196
Fix for Lua's "PlayerSpawn" hook
This fixes how functions for the "PlayerSpawn" Lua hook aren't called when the player respawns at a starpost instead of at a map thing start.
(Note to Lua scripters who may want to adjust their scripts accordingly with this in future, checking if `player.starposttime` is non-zero is the best way to detect if you're spawning at a starpost or not.)
See merge request !198
* Fixed oversight where late joiners may not actually get lives.
* Fixed oversight where zero-livers could spawn in.
* Reinstated flashing because a crawla walked onto one of the spawnpoints and we immediately got a game over.
* Rejiggered the overlay drawer so the printing was consistent between normal spectatorship and game overness.
Polyobject segs should ONLY be drawn if the polyobject itself is in the polylist of a subsector being rendered. That way you won't sometimes see polyobject walls through level boundaries, if you happen to be close enough to their pre-spawn locations outside the level (or in them, if you decided to go on a noclip journey).
* Gave lifedistribution a "Sharing" option to go along with its previous individual and stealing options.
* Made the game over graphic and music only happen if everyone's out of lives if you're sharing or stealing lives.
* Fixed a bug where game over wouldn't come to fruition because it kept on happening each tic of the countdown2.
* Made spectator stuff display in Co-op splitscreen.
* Make setting steallives to true respawn every game overed spectator.
* Make a minimum on the number of lives GetLives can get you.
* Add "You'll steal a life on respawn" to spectator screen.
* Make sure that a life theft always takes you from 0 (or less) lives to 1 life.
* Fix a bracket level typo that meant new Co-op style respawning was being done for all gametypes.
