Blockdata backups

src/main/java/com/volmit/iris/object/IrisBlockData.java

@@ -41,6 +41,10 @@ public class IrisBlockData
 	@Desc("The weight is used when this block data is inside of a list of blockdata. A weight of two is just as if you placed two of the same block data values in the same list making it more common when randomly picked.")
 	private int weight = 1;
 
+	@DontObfuscate
+	@Desc("If the block cannot be created on this version, Iris will attempt to use this backup block data instead.")
+	private IrisBlockData backup = null;
+
 	@DontObfuscate
 	@Desc("Optional properties for this block data such as 'waterlogged': true")
 	private KMap<String, Object> data = new KMap<>();
@@ -81,6 +85,11 @@ public class IrisBlockData
 				return b;
 			}
 
+			if(backup != null)
+			{
+				return backup.getBlockData();
+			}
+
 			return B.get("AIR");
 		});
 	}