Refactor to avoid linear lookup of streamers.

This was a bit of a rabbit hole and took longer than expected,
and I had a stupid bug that took a while to find,
but in the end there are way more lines of code removed than
added, so I'll call it a win. Streamer lookup is now via a Dictionary.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5608 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/io/streamers/LongStreamer.as

@@ -37,11 +37,6 @@ public class LongStreamer extends Streamer
         super(Long, "java.lang.Long");
     }
 
-    override public function createObject (ins :ObjectInputStream) :Object
-    {
-        return new Long();
-    }
-
     override public function writeObject (obj :Object, out :ObjectOutputStream) :void
     {
         var longy :Long = (obj as Long);