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/media/image/Quantize.java

@@ -754,6 +754,7 @@ public class Quantize {
                         SQUARES[((color >>  0) & 0xFF) - b + MAX_RGB]);
             }
 
+            @Override
             public String toString() {
                 StringBuilder buf = new StringBuilder();
                 if (parent == this) {