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/cast/builder/SpritePanel.java

@@ -55,7 +55,7 @@ public class SpritePanel extends JPanel
         _model.addListener(this);
     }
 
-    // documentation inherited
+    @Override
     public void paintComponent (Graphics g)
     {
         super.paintComponent(g);
@@ -67,7 +67,7 @@ public class SpritePanel extends JPanel
         }
     }
 
-    // documentation inherited
+    @Override
     public void doLayout ()
     {
         super.doLayout();