Removed the allow-extra-data-values option.

This reverts parts of e477141.
Data values could never go past 15 anyway,
making the option pointless and misleading.

src/main/java/com/sk89q/worldedit/LocalConfiguration.java

@@ -110,7 +110,6 @@ public abstract class LocalConfiguration {
     public boolean showFirstUseVersion = true;
     public int butcherDefaultRadius = -1;
     public int butcherMaxRadius = -1;
-    public boolean allowExtraDataValues = false;
     public boolean allowSymlinks = false;
 
     /**