Only numframes so far though, as there's already a function for what spriteframe provides.

(oddly enough, this actually revealed some secret file dependencies previously included via r_things.h! I also needed to include d_player.h in r_skins.h itself it seems)

* Fixed an unused variable warning in lua_skinlib.c.
- fixed post-level cutscenes playing when you get game over in MP (still kinda on-topic)
Also with apologies to MI:
- golden egg statue mode for tutorial, since the grey doesn't contrast enough with the blue and lime green
- fixed closed captions for replaced player sounds being incorrect
- fixed closed captions overlapping tutorial text

Also:
* SPR2_XTRA - instead of defining lumpnames in S_SKIN, those kinds of assets can just be bundled into the spriteset. Required for ending cutscene stuff, I guess, but also done for HUD life icon and character select image (aside from Sonic&Tails, still SOC'd in).
* Minor oversights in SPR2 support corrected.
* Better evaluation, featuring ending assets.
* Intro has warping-in blackrock, reusing ending assets.
* Cutscene text now supports lowercase (intro and custom).
* Disable the asset-fucking "gamma correction" I put in over two years ago when implementing colour cube. (This is the only thing I could move into another branch if you MUST, but it's basically invisble in the diff so w/e.)
* Don't blank the screen if the top left pixel of a screen-covering patch is transparent. (Checked via nonzero topdelta for first column)

Bugs:
* OPENGL ONLY: The first ~20 frames of both endings are fucked. A little help here? Might be HWR_DrawFadeFill's fault, which I just created. OR it could be in f_finale, but I doubt it, since it doesn't appear in Software.

Smiles follow-mobj initial support! Still using a Lua hook to follow closely behind, but now it doesn't need to be a generic thinkframe. Woo!

* if you can turn SF_SUPER, flash your skin's supercolor, otherwise be your normal color
* if your skin doesn't have a SPR2_NGT0 (horizontal fly), use Sonic's (this will hopefully be replaced by 2.2 with sprites of NiGHTS themselves)
* MT_NIGHTSCHAR made irrelevant, everything follows actor->target instead of actor->target->tracer now
* emerald is now player->mo->tracer instead of player->mo->tracer->target
* nightopian helpers flash for the 35 tics before they disappear
* nights capsule makes boss explosions/noises now (i can change it back i just like it better)
* drill off into the sky instead of fly up in floating pose (but no noise yet)

ALSO:
* default maxdash is now 70
* forgot to add supercolor to lua, it is there now
* SPR2_SMSL renamed to SPR2_SSTN (stun)
* any player with a skincolor that's in the super range is set to FF_FULLBRIGHT at state-set time, so no need to keep super players non-fullbright just because they use spin stuff

New S_SKIN attribute - "camerascale", another float. Acts as a scale modifier to t_cam_dist and t_cam_height.

* radius - sets the player's radius for that skin.
* height - sets the player's normal height for that skin.
* spinheight - sets the player's spinheight for that skin.
* shieldscale - see http://i.imgur.com/BQ5DhKC.png for justification

(no actual SLOC changes)

The idea is for the layman Lua user to understand better what range of values to use for mobj types, states, sfxs, player #s etc. Additionally, mobjinfo/states/sfxinfo/hudinfo tables all now have actual bound checks when accessing/editing them. Yikes, why didn't they have any before?!

Angles now go from 0 to 0xFFFF (360 degrees == FRACUNIT) instead
of using a full UINT32. Lua only has one number type, so signedness
gets in the way of using angle_t directly. This handling of angles
matches up with how ZDoom ACS scripting and the like does it.

I also changed all the integer casts and pushes of fixed_t to
their own macro in preperation for possible future seperation.