Avoid a compiler bug with constrained Set extensions. Add a notification observation to Account when unread count changes.

Frameworks/Account/Account.swift

@@ -135,6 +135,8 @@ public final class Account: DisplayNameProvider, UnreadCountProvider, Container,
 
 		NotificationCenter.default.addObserver(self, selector: #selector(downloadProgressDidChange(_:)), name: .DownloadProgressDidChange, object: nil)
 
+		NotificationCenter.default.addObserver(self, selector: #selector(unreadCountDidChange(_:)), name: .UnreadCountDidChange, object: nil)
+		
 		pullObjectsFromDisk()
 	}
 	
@@ -286,6 +288,11 @@ public final class Account: DisplayNameProvider, UnreadCountProvider, Container,
 		NotificationCenter.default.post(name: .AccountRefreshProgressDidChange, object: self)
 	}
 	
+	@objc func unreadCountDidChange(_ note: Notification) {
+		
+		
+	}
+
 	// MARK: - Equatable
 
 	public class func ==(lhs: Account, rhs: Account) -> Bool {
@@ -444,10 +451,10 @@ private extension Account {
         unreadCount = calculateUnreadCount(children)
     }
     
-    func noteStatusesForArticlesDidChange(articles: Set<Article>) {
+    func noteStatusesForArticlesDidChange(_ articles: Set<Article>) {
         
-        let feeds = articles.feeds()
+		let feeds = Set(articles.flatMap { $0.feed })
-        let statuses = articles.statuses()
+		let statuses = Set(articles.map { $0.status })
         
         // .UnreadCountDidChange notification will get sent to Folder and Account objects,
         // which will update their own unread counts.

Frameworks/Account/DataExtensions.swift

@@ -42,13 +42,3 @@ public extension Article {
 	}
 }
 
-public extension Set where Element == Article {
-    
-    public func feeds() -> Set<Feed> {
-        return Set(flatMap { $0.feed })
-    }
-    
-    public func statuses() -> Set<ArticleStatus> {
-        return Set(map { $0.articleStatus })
-    }
-}