Some user name auto completion.

Make some progress on #106

src/spectralroom.h

@@ -2,6 +2,7 @@
 #define SpectralRoom_H
 
 #include "room.h"
+#include "spectraluser.h"
 
 #include <QObject>
 #include <QTimer>
@@ -74,6 +75,8 @@ class SpectralRoom : public Room {
 
   Q_INVOKABLE void getPreviousContent(int limit = 10);
 
+  Q_INVOKABLE QVariantList getUsers(const QString& prefix);
+
  private:
   QString m_cachedInput;
   QSet<const QMatrixClient::RoomEvent*> highlights;