Restored glass model that implements the uv shift.

Added a way to register built-in models to support this.

src/main/java/appeng/bootstrap/components/BuiltInModelComponent.java

@@ -0,0 +1,39 @@
+package appeng.bootstrap.components;
+
+
+import java.util.HashMap;
+import java.util.Map;
+
+import com.google.common.base.Preconditions;
+
+import net.minecraftforge.client.model.IModel;
+import net.minecraftforge.client.model.ModelLoaderRegistry;
+import net.minecraftforge.fml.relauncher.Side;
+import net.minecraftforge.fml.relauncher.SideOnly;
+
+import appeng.client.render.model.BuiltInModelLoader;
+
+
+@SideOnly( Side.CLIENT )
+public class BuiltInModelComponent implements PreInitComponent
+{
+
+	private final Map<String, IModel> builtInModels = new HashMap<>();
+
+	private boolean hasInitialized = false;
+
+	public void addModel( String path, IModel model )
+	{
+		Preconditions.checkState( !hasInitialized );
+		builtInModels.put( path, model );
+	}
+
+	@Override
+	public void preInitialize( Side side )
+	{
+		hasInitialized = true;
+
+		BuiltInModelLoader loader = new BuiltInModelLoader( builtInModels );
+		ModelLoaderRegistry.registerLoader( loader );
+	}
+}