Wizards: allow more flexibility when adding a project as a subproject

This patch allows a wizard to choose a "parent" project
already in the intro page.

Change-Id: Id7b010ba43f3a6aa723e5ced865a4afe96d6e40a
Reviewed-by: Alessandro Portale <alessandro.portale@nokia.com>

src/plugins/projectexplorer/projectwizardpage.h

@@ -69,6 +69,9 @@ public:
     void setFilesDisplay(const QString &commonPath, const QStringList &files);
 
     void setAddingSubProject(bool addingSubProject);
+
+    void setProjectComoBoxVisible(bool visible);
+
 protected:
     virtual void changeEvent(QEvent *e);