FF_ANIMATE additions: globally synced animations
FF_GLOBALANIM = makes the animation synced to the level's timer, so all objects will display the same frame at the same time

I mean, doesn't that look so much prettier?
There's also some changes to FF_MIDDLESTARTCHANCE (FF_ANIMATE behavior was split due to not acting consistent between that and SPR2 behavior).
See merge request !46
Animated sky support
What it says on the tin: skies can be animated textures now. Just set them up as normal animated textures (keeping in mind the starting texture still has to comply with the SKYn/SKYnn/SKYnnn naming format) and hey presto, your sky animates.
See merge request !34
* Camerascale, shieldscale, height and spinheight are now player attributes which are set to the skin attribute on skin change, not read directly from the skin.
* P_GetPlayerHeight and P_GetPlayerSpinHeight are now macros instead of functions.
* Extra protection against switching to a locked skin.
* flips the sprite ala MFE_VERTICALFLIP except you don't need to flip the direction of gravity for the object just to draw upside down
* stacks properly with reverse gravity
* Sets the sortscale of the mobj to that of its tracer.
* Basically, Smiles' tails won't clip through shields thanks to this.
* http://gfycat.com/GraveGlassEwe
* Also has support for chains of MF2_LINKDRAW!
More slope fixes (aka sorry guys I made another quick SUGOI fix)
Another slopes fix branch!
This branch currently includes a fix for:
* Knuckles gliding into a slope while in 2D mode causes him to try to "climb" on air above them, if the original non-sloped height is higher. Unfortunately he still tries to grab onto places that he can't really climb on, but at least now it's on the slope itself and not in mid-air lol. This issue is encountered in SUGOI's Retro Hill Zone, if you want to check for yourselves.
* Bustable FOF-busting code for both players AND pushables not accounting for slopes
* (Unrelated to slopes): Fix FF_SHATTERBOTTOM FOFs acting like THZ goop when stood on; I added this fix as a bonus because I encountered it in a test map of mine for the bustables fix
(Other fixes may or may not appear here in the near future, I haven't decided yet. Don't wait on me to get in any further fixes before merging, that said)
See merge request !110
Last-minute NiGHTS exiting bugfix
One single-line fix concerning the end of NiGHTS maps. Extremely small, literally zero side effects here, the only reason I'm not committing directly to master (aside from ettiquette) is that I don't have the ability to do so.
* The NiGHTS drone had a single tic of visibility when you hit the goal, which is evident stepping frame by frame through http://gfycat.com/ComplicatedComposedAoudad (the contents of which may or may not make it into 2.2). This is no longer the case.
See merge request !100