DefaultPrefService: add TODO

Added comments detailing planned future for the pref service.

Author: hinerm

src/main/java/org/scijava/preferences/DefaultPrefService.java

@@ -53,6 +53,16 @@
 @Plugin(type = Service.class)
 public class DefaultPrefService extends AbstractPrefService {
 
+	// TODO - with the conversion from a static utility class to a service, we
+	// have unfortunately lost some power to adapt behavior to individual data
+	// types - either the whole service is superceded, or it's not. For example,
+	// see the saveValue/loadValue of the ModuleItem class, where each item could
+	// decide how it was saved and loaded.
+	// Thus it would be nice to refactor this service to use the Handler pattern,
+	// such that there would just be a few base put/get methods that delegated
+	// to appropriate handlers. Then the handlers of a single type could be
+	// provided and overridden.
+
 	// -- Global preferences --
 
 	@Override