* Made the name of P_PrepareSlopeToWallTransfer (now P_GetWallTransferMomz) make sense.
* Bugfixed the case where you couldn't reliably guess the angle of the wall you just hit.
* Seriously reworked a lot of stuff behind the scenes, thanks to Red's comments.
* More consistent behaviour.
* Launching power is now scaled to the slope's angle relative to the wall you hit, so no massive launches when you hit the side of a steep slope.
* The code is a lot messier and the function name doesn't make any sense any more, so I need to clean that up in the morning.
* Need to figure out how to prevent tiny launches that uncurl you when spindashing up against walls.
* Spindashing trails now takes into account vertical momentum as well as horizontal - it was stupid not seeing your spintrail just because you weren't moving very fast horizontally!
No exe uploaded because it's almost 2am.
Also, the teetering angle on slopes is now FRACUNIT/2 because there's literally no way to stand still on a slope that steep unless it doesn't have physics.
Compiling errors fixed in this commit:
* Various cases of mixed declaration and statement code
* Implicit declaration of slope functions (read: you forgot to put "include "p_slopes.h" in MORE than a few places)
* an odd case of a bad fixed_t to float typecase, cause by using P_GetZAt directly inside FIXED_TO_FLOAT
* a few minor cases of bad unsigned-signed comparisons
* no prototypes for some of the new slope functions. For goodness sake Red, this is basic stuff!
These functions were already here before, and I /swear/ the slope
physics became slightly less glitchy after switching to them...
Only issue is the slope plane mapping code hasn't been properly
converted yet, so they don't render properly for now.
