Qml Debugger: Enable debugging qml+cpp standalone applications

A new debugger engine, QmlCppEngine, is introduced, which wraps gdb
and qml engines into one. Alternatively, if using Windows, Cdb is used
instead of Gdb.

Most of the debugger ui switcher is now rewritten, and it is tailored
for the QML and CPP layout case, the only one supported anyway.

Reviewed-by: hjk

src/plugins/debugger/debuggerrunner.h

@@ -117,6 +117,10 @@ public:
                                  QString *settingsCategory = 0,
                                  QString *settingsPage = 0);
 
+    static bool isQmlProject(RunConfiguration *config);
+    static bool isCurrentProjectQmlCppBased();
+    static bool isCurrentProjectCppBased();
+
 private slots:
     void handleFinished();
 
@@ -130,6 +134,8 @@ private:
     Internal::DebuggerEngine *m_engine;
     const QWeakPointer<RunConfiguration> m_myRunConfiguration;
     bool m_running;
+    bool m_started;
+    bool m_isQmlProject;
     DebuggerEngineType m_enabledEngines;
     QString m_errorMessage;
     QString m_settingsIdHint;