Now notifications have actions! Some more usefull functions to roster model

ui/models/contact.cpp

@@ -155,6 +155,16 @@ void Models::Contact::removePresence(const QString& name)
     }
 }
 
+Models::Presence * Models::Contact::getPresence(const QString& name)
+{
+    QMap<QString, Presence*>::iterator itr = presences.find(name);
+    if (itr == presences.end()) {
+        return nullptr;
+    } else {
+        return itr.value();
+    }
+}
+
 void Models::Contact::refresh()
 {
     QDateTime lastActivity;