* Bubblewrap shield bounce now no longer allows thokking post-bounce, but still allows bouncing
* plus a bunch of tiny changes to clean up code around the place.
* Some shield sounds swapped (can be reverted later).
* Partial implementation of S3K shield abilities.
* The ability to elemental-groundpound onto gold monitors without going straight through them.
* Force shield ability removed because nobody could agree on it, we'll keep it blank until another idea can get through the disagreement juggernaut.
* shields give you 1000 points
* redundant shields don't make you puase
* checkpoints give you 2000 points
* falling down a deathpit is just falling, not bouncing
Fixes to horizontal spring collision
Fixed various issues arising from collision with exclusively horizontal springs. Thamks to @Inuyasha for the heads up! Of note:
* If you hold down your jump button whilst jumping into it, you no longer immediately use your ability.
* Characters with (CA_DOUBLEJUMP && CA2_MULTIABILITY) or CA_FLOAT or CA_HOVER no longer lose track of their jump count.
Also:
* Upped the strength of info.c's red and yellow horizontal springs.
See merge request !41
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
* introducing the new friend, SH_FORCEHP (which is used as a bitmask to get the extra hitpoints of a force-shield user)
* P_DamageMobj now considers the unimplemented shield constants as well as the implemented ones.
* When not pressing any direction, you now go backwards by default - to emphasise that this is primarily for defensive, not offensive, purposes.
* The camera can now handle the player going backwards without them going completely off-screen.
* Fixed some overzealous checks.
* The spinfire ring is now capable of damaging enemies. (god, what a terrible hack this is)
* When ground pounding, you now bounce off the floor a little bit to make the ability less spammable.
* The Dodge Dash
* Allows you to dash - no control, no falling, no key response - for 2 + (number of extra shield hitpoints) tics.
* If you're holding movement keys down, you dash in the direction you're holding - otherwise, you dash directly forward.
* You're spinning (spindash spin, not jump spin) until your dash is over, then your momentum is cut down significantly and you end up in falling frames.
* It may not necessarily be super useful for Sonic, but it helps the other characters.
* http://gfycat.com/BogusFailingFritillarybutterfly
* http://gfycat.com/PoliticalIdealisticBallpython (outdated speed, shows any direction)
* GFZ3 Eggmobile's laser won't change its angle when you move left and right anymore.
* Changed because its ability to move quickly was extremely punishing for new players (see ProJared's youtube video on the matter).
* http://gfycat.com/PassionateUnknownAgama (the twitching on the third laser has been fixed since this was recorded)
* GFZ3 Eggmobile will, when too far away from the ground and moving upwards, slow itself down vertically.
* This was punishing and annoying for both old and new players alike.
* http://gfycat.com/ShabbyAncientEarthworm (old values - the typical settling height is slightly lower now)
(the problem was that MT_OVERLAY's default radius and height were never getting changed from 1*FRACUNIT, and that meant that when you spindashed, the game considered it completely below the surface of the flat you were standing on. Since you're not usually clipped on flats that don't belong to FOFs, we didn't notice this issue sooner.)