FEATURE: Allow admins to lock users from TL3 promotion/demotion

Also, update the display logic for the leader promotion screen to
account for the demotion grace period.

app/models/trust_level3_requirements.rb

@@ -16,13 +16,15 @@ class TrustLevel3Requirements
                 :posts_read_all_time, :min_posts_read_all_time,
                 :num_flagged_posts, :max_flagged_posts,
                 :num_likes_given, :min_likes_given,
-                :num_likes_received, :min_likes_received
+                :num_likes_received, :min_likes_received,
+                :trust_level_locked, :on_grace_period
 
   def initialize(user)
     @user = user
   end
 
   def requirements_met?
+    return false if trust_level_locked
     !@user.suspended? &&
     days_visited >= min_days_visited &&
     num_topics_replied_to >= min_topics_replied_to &&
@@ -37,6 +39,7 @@ class TrustLevel3Requirements
   end
 
   def requirements_lost?
+    return false if trust_level_locked
     @user.suspended? ||
     days_visited < min_days_visited * LOW_WATER_MARK ||
     num_topics_replied_to < min_topics_replied_to * LOW_WATER_MARK ||
@@ -50,6 +53,14 @@ class TrustLevel3Requirements
     num_likes_received < min_likes_received * LOW_WATER_MARK
   end
 
+  def trust_level_locked
+    @user.trust_level_locked
+  end
+
+  def on_grace_period
+    @user.on_leader_grace_period?
+  end
+
   def days_visited
     @user.user_visits.where("visited_at > ? and posts_read > 0", TIME_PERIOD.days.ago).count
   end