Add in @Overrides across the board, clean up the comments around them some, and remove

unneeded imports.
I've got partially completed patches for narya & vilya, too, but nenya was the 
only one that wound up in a decent state after a friday evening puttering at it,
killing time waiting on other things to finish.


git-svn-id: svn+ssh://src.earth.threerings.net/nenya/trunk@572 ed5b42cb-e716-0410-a449-f6a68f950b19

src/java/com/threerings/miso/util/ObjectSet.java

@@ -133,9 +133,7 @@ public class ObjectSet
         return info;
     }
 
-    /**
-     * Returns a string representation of this instance.
-     */
+    @Override
     public String toString ()
     {
         StringBuilder buf = new StringBuilder("[");