Implement since id as a parameter to limit the number returned

Frameworks/Account/FeedProvider/Twitter/TwitterFeedProvider.swift

@@ -177,6 +177,10 @@ public struct TwitterFeedProvider: FeedProvider {
 		var parameters = [String: Any]()
 		var isSearch = false
 		
+		if let sinceToken = webFeed.sinceToken, let sinceID = Int(sinceToken) {
+			parameters["since_id"] = sinceID
+		}
+		
 		switch urlComponents.path {
 		case "", "/", "/home":
 			parameters["count"] = 100
@@ -208,8 +212,11 @@ public struct TwitterFeedProvider: FeedProvider {
 
 		retrieveTweets(api: api, parameters: parameters, isSearch: isSearch) { result in
 			switch result {
-			case .success(let tweets):
-				let parsedItems = self.makeParsedItems(webFeed.url, tweets)
+			case .success(let statuses):
+				if let sinceID = statuses.first?.idStr {
+					webFeed.sinceToken = sinceID
+				}
+				let parsedItems = self.makeParsedItems(webFeed.url, statuses)
 				completion(.success(parsedItems))
 			case .failure(let error):
 				completion(.failure(error))

Frameworks/Account/WebFeed.swift

@@ -153,6 +153,15 @@ public final class WebFeed: Feed, Renamable, Hashable {
 		}
 	}
 	
+	public var sinceToken: String? {
+		get {
+			return metadata.sinceToken
+		}
+		set {
+			metadata.sinceToken = newValue
+		}
+	}
+
 	public var externalID: String? {
 		get {
 			return metadata.externalID

Frameworks/Account/WebFeedMetadata.swift

@@ -27,6 +27,7 @@ final class WebFeedMetadata: Codable {
 		case isNotifyAboutNewArticles
 		case isArticleExtractorAlwaysOn
 		case conditionalGetInfo
+		case sinceToken
 		case externalID = "subscriptionID"
 		case folderRelationship
 	}
@@ -111,6 +112,14 @@ final class WebFeedMetadata: Codable {
 		}
 	}
 	
+	var sinceToken: String? {
+		didSet {
+			if externalID != oldValue {
+				valueDidChange(.externalID)
+			}
+		}
+	}
+	
 	var externalID: String? {
 		didSet {
 			if externalID != oldValue {