- make the FWarpTexture class local to the software renderer.

This class has only meaning for software-based warping so it doesn't have to be a part of the FTexture hierarchy.
Making it a subclass of FSoftwareTexture is fully sufficient.

src/textures/texture.cpp

@@ -45,7 +45,6 @@
 #include "c_dispatch.h"
 #include "v_video.h"
 #include "m_fixed.h"
-#include "textures/warpbuffer.h"
 #include "hwrenderer/textures/hw_material.h"
 #include "hwrenderer/textures/hw_ihwtexture.h"
 
@@ -239,11 +238,6 @@ void FTexture::Unload()
 //
 //==========================================================================
 
-bool FTexture::CheckModified (FRenderStyle)
-{
-	return false;
-}
-
 FTextureFormat FTexture::GetFormat()
 {
 	return TEX_Pal;