Add handoff support for issues (#331)

* Add handoff support for issues

* Update Info.plist

Classes/View Controllers/UIViewController+UserActivity.swift

@@ -0,0 +1,40 @@
+//
+//  UIViewController+UserActivity.swift
+//  Freetime
+//
+//  Created by Bas Broek on 20/09/2017.
+//  Copyright © 2017 Ryan Nystrom. All rights reserved.
+//
+
+import Foundation
+
+protocol UserActivitySupporting {
+    var activityName: String { get }
+    var activityTitle: String { get }
+}
+
+struct HandoffInformator: UserActivitySupporting {
+    let activityName: String
+    let activityTitle: String
+    let url: URL
+}
+
+extension UIViewController {
+    
+    func setupUserActivity(with informator: HandoffInformator) {
+        let activity = NSUserActivity(activityType: "\(Bundle.main.bundleIdentifier ?? "").\(informator.activityTitle)")
+        activity.title = NSLocalizedString(informator.activityTitle, comment: "")
+        activity.webpageURL = informator.url
+        activity.isEligibleForHandoff = true
+        self.userActivity = activity
+        self.userActivity?.becomeCurrent()
+    }
+    
+    func resignUserActivity() {
+        userActivity?.resignCurrent()
+    }
+    
+    func invalidateUserActivity() {
+        userActivity?.invalidate()
+    }
+}