Added SDSIO and delete to SDS map

src/com/flaremicrosystems/sds/SDSNameMapType.java

@@ -141,6 +141,11 @@ public class SDSNameMapType extends SDSObject<TreeMap<String, SDSObject<?>>>{
 			value.remove(name);
 		else value.put(name, sdsObject);
 	}
+	
+	public void delete(String name)
+	{
+		put(name, null);
+	}
 
 	@Override
 	public int getByteLength() {
@@ -188,4 +193,6 @@ public class SDSNameMapType extends SDSObject<TreeMap<String, SDSObject<?>>>{
 	public boolean hasOfType(String name, Class<?> tester) {
 		return this.value.containsKey(name) && tester.isInstance(this.value.get(name));
 	}
+
+	
 }