QmlProfiler: Support local connections on Qt >= 5.6

This removes the need to receive messages from the application via
stderr. The "Connecting to socket" is still parsed, but only for
diagnostic purposes. If it doesn't arrive, the profiling will still
work.

Change-Id: I022691293da2a1e671ba1263bc76e4044bf1a5b7
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

src/plugins/qmlprofiler/qmlprofilerclientmanager.h

@@ -52,6 +52,7 @@ public:
 
     void registerProfilerStateManager(QmlProfilerStateManager *profilerState);
     void setTcpConnection(QString host, quint64 port);
+    void setLocalSocket(QString file);
 
     void clearBufferedData();
     void discardPendingData();
@@ -65,7 +66,8 @@ signals:
     void connectionClosed();
 
 public slots:
-    void connectClient(quint16 port);
+    void connectTcpClient(quint16 port);
+    void connectLocalClient(const QString &file);
     void disconnectClient();
 
 private slots:
@@ -89,7 +91,7 @@ private:
 
     void connectToClient();
 
-    void enableServices();
+    void createConnection();
     void connectClientSignals();
     void disconnectClientSignals();