Nothing else uses these, and we don't even bother exporting them

to Lua.  Remove them to eliminate an SDimensions.h dependency.

stepmania/src/RageDisplay.cpp

@@ -472,7 +472,7 @@ void RageDisplay::LoadMenuPerspective( float fovDegrees, float fVanishPointX, fl
 	if( fovDegrees == 0 )
 	{
  		float left = 0, right = SCREEN_WIDTH, bottom = SCREEN_HEIGHT, top = 0;
-		g_ProjectionStack.LoadMatrix( GetOrthoMatrix(left, right, bottom, top, SCREEN_NEAR, SCREEN_FAR) );
+		g_ProjectionStack.LoadMatrix( GetOrthoMatrix(left, right, bottom, top, -1000, +1000) );
  		g_ViewStack.LoadIdentity();
 	}
 	else

stepmania/src/ScreenDimensions.h

@@ -28,9 +28,6 @@ namespace ScreenDimensions
 
 #define FullScreenRectF RectF(SCREEN_LEFT,SCREEN_TOP,SCREEN_RIGHT,SCREEN_BOTTOM)
 
-#define	SCREEN_NEAR		(-1000)
-#define	SCREEN_FAR		(1000)
-
 #define	ARROW_SIZE		(64)
 
 #endif