Let's let the unread features determine how to scroll

I profiled this and on a 700 post thread, 30% time was spent trying
to figure out if we needed to scroll to the top of the thread or
not. I don't feel that's acceptable.

builds/4chan-X.user.js

@@ -12120,8 +12120,7 @@
       Main.callbackNodes(Thread, [thread]);
       Main.callbackNodes(Post, posts);
       Navigate.ready();
-      Navigate.buildThread();
-      return Header.scrollToIfNeeded($('.board'));
+      return Navigate.buildThread();
     },
     buildThread: function() {
       var board;

builds/crx/script.js

@@ -12109,8 +12109,7 @@
       Main.callbackNodes(Thread, [thread]);
       Main.callbackNodes(Post, posts);
       Navigate.ready();
-      Navigate.buildThread();
-      return Header.scrollToIfNeeded($('.board'));
+      return Navigate.buildThread();
     },
     buildThread: function() {
       var board;

src/General/Navigate.coffee

@@ -274,7 +274,6 @@ Navigate =
     Navigate.ready()
 
     Navigate.buildThread()
-    Header.scrollToIfNeeded $ '.board'
 
   buildThread: ->
     board = $ '.board'