QmlProfiler: remove useless signals

Sending a signal for every model when clearing or loading data is not
very smart.

Change-Id: Ifc81d74f6b7f93bcd6748a919dfb553050b8d725
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

src/plugins/qmlprofiler/abstracttimelinemodel.cpp

@@ -192,11 +192,6 @@ void AbstractTimelineModel::dataChanged()
     default:
         break;
     }
-
-    emit stateChanged();
-    emit dataAvailable();
-    emit emptyChanged();
-    emit expandedChanged();
 }
 
 bool AbstractTimelineModel::eventAccepted(const QmlProfilerDataModel::QmlEventTypeData &event) const