Add basic ExtensionPoint support.

Shared/ExtensionPoints/ExtensionPointManager.swift

@@ -0,0 +1,49 @@
+//
+//  ExtensionPointManager.swift
+//  NetNewsWire
+//
+//  Created by Maurice Parker on 4/7/20.
+//  Copyright © 2020 Ranchero Software. All rights reserved.
+//
+
+import Foundation
+import FeedProvider
+import RSCore
+
+struct ExtensionPointManager {
+	
+	static let shared = ExtensionPointManager()
+	
+	let marsEdit = SendToMarsEditCommand()
+	let microblog = SendToMicroBlogCommand()
+	let twitter = TwitterFeedProvider()
+	
+	let availableExtensionPoints: [ExtensionPoint]
+	let activeSendToCommands: [SendToCommand]
+	let activeFeedProviders: [FeedProvider]
+	
+	init() {
+		#if os(macOS)
+		#if DEBUG
+		availableExtensionPoints = [marsEdit, microblog, twitter]
+		activeSendToCommands = [marsEdit, microblog]
+		activeFeedProviders = [twitter]
+		#else
+		availableExtensionPoints = [marsEdit, microblog, twitter]
+		activeSendToCommands = [marsEdit, microblog]
+		activeFeedProviders = [twitter]
+		#endif
+		#else
+		#if DEBUG
+		availableExtensionPoints = [twitter]
+		activeSendToCommands = []()
+		activeFeedProviders = [twitter]
+		#else
+		availableExtensionPoints = [twitter]
+		activeSendToCommands = []()
+		activeFeedProviders = [twitter]
+		#endif
+		#endif
+	}
+	
+}