unify(dx8wrapper): Merge unnecessary forward declarations

Author: stephanmeesters

Generals/Code/Libraries/Source/WWVegas/WW3D2/dx8wrapper.h

@@ -95,8 +95,10 @@ class DynamicVBAccessClass;
 class IndexBufferClass;
 class DynamicIBAccessClass;
 class TextureClass;
+class ZTextureClass;
 class LightClass;
 class SurfaceClass;
+class DX8Caps;
 
 #define DX8_RECORD_MATRIX_CHANGE()				matrix_changes++
 #define DX8_RECORD_MATERIAL_CHANGE()			material_changes++