Added a "hand" pseudo block type that uses the currently selected block.

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

@@ -397,7 +397,17 @@ public class WorldEdit {
         int data = -1;
 
         boolean parseDataValue = true;
+        if ("hand".equalsIgnoreCase(testID)) {
+            // Get the block type from the item in the user's hand.
+            final BaseBlock blockInHand = player.getBlockInHand();
+            if (blockInHand.getClass() != BaseBlock.class) {
+                return blockInHand;
+            }
 
+            blockId = blockInHand.getId();
+            blockType = BlockType.fromID(blockId);
+            data = blockInHand.getData();
+        } else {
             // Attempt to parse the item ID or otherwise resolve an item/block
             // name to its numeric ID
             try {
@@ -436,6 +446,7 @@ public class WorldEdit {
             if (!player.getWorld().isValidBlockType(blockId)) {
                 throw new UnknownItemException(arg);
             }
+        }
 
         if (!allowNoData && data == -1) {
             // No wildcards allowed => eliminate them.