Models get updated when userData changes at server

The websocket now notifies the ApiClient, on which several models and
items are listening, when the userData for an user has changed. The UI
on the qml side may automatically updates without any extra effort.

This also resolves a bug where videos didn't resume after +/- 3:40 due
to an integer overflow.

sailfish/qml/pages/itemdetails/VideoPage.qml

@@ -32,6 +32,7 @@ import "../.."
 BaseDetailPage {
     property alias subtitle: pageHeader.description
     default property alias _data: content.data
+    property real _playbackProsition: itemData.userData.playbackPositionTicks
     SilicaFlickable {
         anchors.fill: parent
         contentHeight: content.height + Theme.paddingLarge
@@ -54,13 +55,14 @@ BaseDetailPage {
                 width: parent.width
                 imageSource: Utils.itemImageUrl(ApiClient.baseUrl, itemData, "Primary", {"maxWidth": parent.width})
                 imageAspectRatio: Constants.horizontalVideoAspectRatio
-                playProgress: itemData.UserData.PlayedPercentage / 100
+                favourited: itemData.userData.isFavorite
+                playProgress: itemData.userData.playedPercentage / 100
                 onPlayPressed: pageStack.push(Qt.resolvedUrl("../VideoPage.qml"),
                                               {"itemId": itemId, "itemData": itemData,
                                                   "audioTrack": trackSelector.audioTrack,
                                                   "subtitleTrack": trackSelector.subtitleTrack,
                                                   "startTicks": startFromBeginning ? 0.0
-                                                                    : itemData.UserData.PlaybackPositionTicks })
+                                                                    : _playbackProsition })
             }
 
             VideoTrackSelector {