Provide a remove method in NbtCompound. Discourage getValue().

Added a missing remove method in NbtCompound. In addition, the
getValue() method in NbtCompount has been depreciated. It is far better
to use the put and get methods in NbtCompound instead.

ProtocolLib/src/main/java/com/comphenix/protocol/wrappers/nbt/NbtBase.java

@@ -64,6 +64,9 @@ public interface NbtBase<TType> {
 	 * Is either a primitive {@link java.lang.Number wrapper}, {@link java.lang.String String}, 
 	 * {@link java.util.List List} or a {@link java.util.Map Map}. 
 	 * <p>
+	 * Users are encouraged to cast an NBT compound to {@link NbtCompound} and use its put and get-methods
+	 * instead of accessing its content from getValue().
+	 * <p>
 	 * All operations that modify collections directly, such as {@link java.util.List#add(Object) List.add(Object)} or 
 	 * {@link java.util.Map#clear() Map.clear()}, are considered optional. This also include members in {@link java.util.Iterator Iterator} and 
 	 * {@link java.util.ListIterator ListIterator}. Operations that are not implemented throw a 

ProtocolLib/src/main/java/com/comphenix/protocol/wrappers/nbt/NbtCompound.java

@@ -16,6 +16,10 @@ import java.util.Set;
  * @author Kristian
  */
 public interface NbtCompound extends NbtBase<Map<String, NbtBase<?>>>, Iterable<NbtBase<?>> {
+	@Override
+	@Deprecated()
+	public Map<String, NbtBase<?>> getValue();
+	
 	/**
 	 * Determine if an entry with the given key exists or not.
 	 * @param key - the key to lookup. 
@@ -304,6 +308,13 @@ public interface NbtCompound extends NbtBase<Map<String, NbtBase<?>>>, Iterable<
 	 */
 	public abstract <T> NbtCompound put(String key, Collection<? extends NbtBase<T>> list);
 
+	/**
+	 * Remove the NBT element that is associated with the given key.
+	 * @param key - the key of the element to remove.
+	 * @return The removed element, or NULL if no such element was found.
+	 */
+	public abstract <T> NbtBase<?> remove(String key);
+	
 	/**
 	 * Retrieve an iterator view of the NBT tags stored in this compound.
 	 * @return The tags stored in this compound.

ProtocolLib/src/main/java/com/comphenix/protocol/wrappers/nbt/WrappedCompound.java

@@ -215,6 +215,9 @@ class WrappedCompound implements NbtWrapper<Map<String, NbtBase<?>>>, Iterable<N
 	 */
 	@Override
 	public <T> NbtCompound put(NbtBase<T> entry) {
+		if (entry == null)
+			throw new IllegalArgumentException("Entry cannot be NULL.");
+		
 		getValue().put(entry.getName(), entry);
 		return this;
 	}
@@ -565,6 +568,9 @@ class WrappedCompound implements NbtWrapper<Map<String, NbtBase<?>>>, Iterable<N
 	
 	@Override
 	public NbtCompound put(String key, NbtBase<?> entry) {
+		if (entry == null)
+			throw new IllegalArgumentException("Entry cannot be NULL.");
+		
 		// Don't modify the original NBT
 		NbtBase<?> clone = entry.deepClone();
 		
@@ -583,6 +589,11 @@ class WrappedCompound implements NbtWrapper<Map<String, NbtBase<?>>>, Iterable<N
 		return put(WrappedList.fromList(key, list));
 	}
 	
+	@Override
+	public <T> NbtBase<?> remove(String key) {
+		return getValue().remove(key);
+	}
+	
 	@Override
 	public void write(DataOutput destination) {
 		NbtBinarySerializer.DEFAULT.serialize(container, destination);