actually fix AsyncBlock

worldedit-bukkit/src/main/java/com/boydti/fawe/bukkit/wrapper/AsyncBlock.java

@@ -314,6 +314,21 @@ public class AsyncBlock implements Block {
         return world.getBlock(x, y, z).getMaterial().isLiquid();
     }
 
+    @Override
+    public boolean isBuildable() {
+        return this.getUnsafeBlock().isBuildable();
+    }
+
+    @Override
+    public boolean isBurnable() {
+        return this.getType().isBurnable();
+    }
+
+    @Override
+    public boolean isReplaceable() {
+        return this.getUnsafeBlock().isReplaceable();
+    }
+
     @Override
     public double getTemperature() {
         return this.getWorld().getTemperature(this.getX(), this.getZ());