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/tile/TileSet.java

@@ -35,9 +35,6 @@ import com.threerings.media.image.Colorization;
 import com.threerings.media.image.Mirage;
 import com.threerings.media.image.ImageUtil;
 import com.threerings.media.image.BufferedMirage;
-import com.threerings.media.util.MultiFrameImage;
-import com.threerings.media.util.MultiFrameImageImpl;
-
 import static com.threerings.media.Log.log;
 
 /**
@@ -350,9 +347,7 @@ public abstract class TileSet
         }
     }
 
-    /**
-     * Generates a string representation of the tileset information.
-     */
+    @Override
     public String toString ()
     {
         StringBuilder buf = new StringBuilder("[");