Move armor items to IMeshProvider

Minor change to IMeshProvider allow for this

src/main/java/WayofTime/bloodmagic/client/IMeshProvider.java

@@ -1,9 +1,11 @@
 package WayofTime.bloodmagic.client;
 
 import net.minecraft.client.renderer.ItemMeshDefinition;
+import net.minecraft.util.ResourceLocation;
 import net.minecraftforge.fml.relauncher.Side;
 import net.minecraftforge.fml.relauncher.SideOnly;
 
+import javax.annotation.Nullable;
 import java.util.List;
 
 /**
@@ -12,9 +14,28 @@ import java.util.List;
  */
 public interface IMeshProvider
 {
-
+    /**
+     * Gets the custom ItemMeshDefinition to use for the item.
+     *
+     * @return - the custom ItemMeshDefinition to use for the item.
+     */
     @SideOnly(Side.CLIENT)
     ItemMeshDefinition getMeshDefinition();
 
+    /**
+     * Gets all possible variants for this item
+     *
+     * @return - All possible variants for this item
+     */
     List<String> getVariants();
+
+    /**
+     * If a custom ResourceLocation is required, return it here.
+     *
+     * Can be null if unneeded.
+     *
+     * @return - The custom ResourceLocation
+     */
+    @Nullable
+    ResourceLocation getCustomLocation();
 }