update message bus to support per client filtering

start work on user_tracking_state
fix can_ban? in guardian
expose protected scopes on topic_query we need
move guardian spec to use build as opposed to creating topics / posts / users
start work on user tracking spec

spec/models/user_tracking_state_spec.rb

@@ -0,0 +1,34 @@
+require 'spec_helper'
+
+describe UserTrackingState do
+
+  let(:user) do
+    Fabricate(:user)
+  end
+
+  let(:post) do
+    Fabricate(:post)
+  end
+
+  let(:state) do
+    UserTrackingState.new(user)
+  end
+
+  it "correctly gets the list of new topics" do
+    state.new_list.should == []
+    state.unread_list.should == []
+
+    new_post = post
+
+    new_list = state.new_list
+
+    new_list.length.should == 1
+    new_list[0][0].should == post.topic.id
+    new_list[0][1].should be_within(1.second).of(post.topic.created_at)
+
+    state.unread_list.should == []
+
+    # read it
+
+  end
+end