- made SPROFS a more usable feature.

This was originally invented to fix the sprite offsets for the hardware renderer.
Changed it so that it doesn't override the original offsets but acts as a second set.
A new CVAR has been added to allow controlling the behavior per renderer.

src/textures/jpegtexture.cpp

@@ -250,8 +250,6 @@ FJPEGTexture::FJPEGTexture (int lumpnum, int width, int height)
 : FWorldTexture(NULL, lumpnum)
 {
 	UseType = ETextureType::MiscPatch;
-	LeftOffset = 0;
-	TopOffset = 0;
 	bMasked = false;
 
 	Width = width;