Cosa è cambiato in EDuke32, build per build

Check that texture entries have a non-skybox filename before using it in texcache_fetchmulti.

Add a new pthtyp flag to mark textures that should not be processed by the fixtransparency() hack (which avoids the transparent color blending into a sprite when texture filtering is enabled), such as non-(T)ROR-masking floors and ceilings, white- and mask-walls, paper-skies, and rotatesprite with orientation flag 64. This commit makes sure the flag's status always fits the situation.

Don't test (!usemodels || md_tilehasmodel(picnum, pal) < 0) in eligible_for_tileshades (called only from getshadefactor) because getshadefactor is only called when a model is *not* being drawn, and therefore results in incorrect shading when drawing a tile with a model defined and models enabled to the screen or as a skybox.

make flipping closer to classic.