What changed in EDuke32, build by build

Revert a number of changes from r6929 and r6930 that are no longer necessary.

Temporary workaround for palette or GL surface issue wherein launching Mapster32 into 2d mode produces a black screen until switching to 3d mode and back

Fix crash in Mapster32 when switching from GL 3d mode to 2d mode.

Fix issue with viewing the player sprite through a security camera

sdlayer.cpp: don't alter desktop composition using win_setvideomode() if we're creating an SDL window for rendering GL

When OpenGL is available, prefer using the new glsurface to blit the classic renderer's 8-bit buffer to the screen.

astub.cpp: fix issue where globalpal was not declared if polymost.h was not included

Don't spawn hardcoded Duke3D debris/guts/glass sprites when compiled as EDUKE32_STANDALONE

engine.cpp: fix issue introduced in r6905 where voxels with fractional scaling would not be handled correctly in Polymost

tiles.cpp: fix texcache.cpp:CLEAR_GL_ERRORS() hang on some drivers when trying to create GL textures for tiles when we have no GL context.

engine.cpp: fix issue with voxmodel_t voxels not having their scale set properly due to defs being processed before PolymostProcessVoxels()

engine.cpp: fix classicDrawVoxel() positioning bugs by:

make setting a sector's .wallptr call setfirstwall() instead of setting it directly and corrupting the map

Revert r6526 and r6527. This restores the longstanding behavior of the killit command, and setting sprites' xrepeat to zero, to not actually delete sprites unless their statnum is STAT_ACTOR or STAT_MISC. Be sure to set a sprite's statnum to one of these statnums if you want it to be deleted.

engine.cpp/.h: clean up & fix lintersect(). Additionally, add support for finding intersections of collinear line segments.

polymost_bindPth(): Fix issue where non-indexed colour, non-hightile textures (including those with polytintflags HICTINT_USEONART or HICTINT_ALWAYSUSEART) would not render correctly while r_useindexedcolortextures is set.

second attempt at preventing extra wall points from being inserted on some walls with the batch point insert tool

in tile selector, make backspace set palette to 0

use object's current palette on tile selection screen and allow cycling object palettes from tile selection screen with - and =

use sc_XXX defines from scancodes.h instead of unlabeled hex scancodes when checking keystatus[]

Fix Mapster32 bug where sometimes you'd get two points instead of one when pressing enter to insert points where the lines intersect with the wall drawing tool

Engine function name cleanup round 2

Fix NORM_(SPRITE|WALL|SECTOR) macros to use MAX$1 instead of ARRAY_SIZE, which would fail due to the structs not being statically allocated.

Temporarily remove the option to enable texture filtering when building with EDUKE32_STANDALONE until indexed colour texture rendering supports filtering.

Fix hitradius performance when affecting tons of walls