OpenGL slope fixes again
This branch just adds the relevant code for OpenGL to properly check slopes regarding "closed door" segs (those between two sectors that cannot be crossed normally) and "window" segs (those between two sectors of differing plane heights that you CAN cross, which would probably display top or bottom textures), so you don't get HOMs when the the slopes create a closed door even though the normal sector heights wouldn't or something.
(if you couldn't understand that, my slopes test map shows what I mean to the right of the player start: https://dl.dropboxusercontent.com/u/25409000/2.1/mi-slopetest.wad)
See merge request !81
Basically this makes sure numwadfiles is updated before loading the SOC/Lua scripts, so if a Lua script calls COM_BufInsertText with the contents "addfile scr_mysticrealm.wad" it can't overwrite the last written wadfile slot! Not that COM_BufInsertText really should be used like that to begin with
*Didn't take into account object scale
*Doubled force when on the ground (ignore what the comment of the line I moved says, it was relevant for slopes...)
This also led to a mistake with slopes, where I was double-multiplying by the gravity constant to get half (because of a quirk of numbers...)
Also took the opportunity to nuke or otherwise neuter a bunch of Kalaron's bizzare ramblings (most are questions which have long-been answered by Red's efforts) at the same time.
*The No Physics flag now works (Red, you might want to doublecheck this to see whether I haven't missed any eosteric stuff out). Going downhill is a little bumpy, and I'm not sure whether that's good or not. Someone help me out here?
*The SRB2CB typeshims are now behind #ifdef ESLOPE_TYPESHIM instead of #if 1 for easier disabling.
*Slopes' downhill thrusts are now scaled with regards to object gravity. This is actually untested in gravities other than normal and reverse normal but it's one line which can be easily reverted in that circumstance. I also checked with MI to make sure this is how it's calculated elsewhere, so fingers crossed this doesn't cause any edge cases.
*As a consequence of the above point, there's now a function in p_mobj.c/h that returns an object's internal gravity - seperated out from the logic of P_CheckGravity, which really didn't need to be so monolithic. Multiply by global gravity to get the thrust. This should probably be available to Lua somehow, but I have absolutely no idea where to start with that. Wolfs, maybe?
Non-comprehensive test file available at /toaster/slptst3.wad on the ftp.
