Expose RenderPathCommand and RenderTargetInfo as Urho public API.

Source/Urho3D/Graphics/RenderPath.h

@@ -62,7 +62,7 @@ enum RenderTargetSizeMode
 };
 
 /// Rendertarget definition.
-struct RenderTargetInfo
+struct URHO3D_API RenderTargetInfo
 {
     /// Construct.
     RenderTargetInfo() :
@@ -102,7 +102,7 @@ struct RenderTargetInfo
 };
 
 /// Rendering path command.
-struct RenderPathCommand
+struct URHO3D_API RenderPathCommand
 {
     /// Construct.
     RenderPathCommand() :