Update SpongeSchematic format to version 2.

Allows saving and loading entities and biomes.

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgePlatform.java

@@ -64,6 +64,12 @@ class ForgePlatform extends AbstractPlatform implements MultiUserPlatform {
         return ForgeRegistries.getInstance();
     }
 
+    @Override
+    public int getDataVersion() {
+        // TODO technically available as WorldInfo#field_209227_p but requires a world ref?
+        return 1631;
+    }
+
     @Override
     public boolean isValidMobType(String type) {
         return net.minecraftforge.registries.ForgeRegistries.ENTITIES.containsKey(new ResourceLocation(type));