Add a stack window menu entry to display QML stack frame.

Add language field to stack frame.
Add virtual for loading QML stack invoked by stack window
context menu, implement for CDB, GDB.

Task-number: QTCREATORBUG-11144

Change-Id: Ic39be3978b40d96ed18cb69a8355296ec572ece7
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/debugger/stackhandler.h

@@ -67,6 +67,7 @@ public:
     ~StackHandler();
 
     void setFrames(const StackFrames &frames, bool canExpand = false);
+    void prependFrames(const StackFrames &frames);
     const StackFrames &frames() const;
     void setCurrentIndex(int index);
     int currentIndex() const { return m_currentIndex; }