TreeModel: Make item flags configurable in "group header" constructor

Default to 'editable' (not selectable), intentionally changes behavior
in the Kits, Compilers and Debugger option pages, but brings it more
in line with Qt version.

Change-Id: I71739a5d61c9980fc6da729dcb59b0900047f066
Reviewed-by: Christian Stenger <christian.stenger@theqtcompany.com>
Reviewed-by: hjk <hjk@theqtcompany.com>

src/libs/utils/treemodel.cpp

@@ -616,9 +616,9 @@ TreeItem::TreeItem()
 {
 }
 
-TreeItem::TreeItem(const QStringList &displays)
+TreeItem::TreeItem(const QStringList &displays, int flags)
     : m_parent(0), m_model(0), m_displays(new QStringList(displays)), m_lazy(false), m_populated(false),
-      m_flags(Qt::ItemIsEnabled|Qt::ItemIsSelectable)
+      m_flags(flags)
 {
 }
 

src/libs/utils/treemodel.h

@@ -49,7 +49,7 @@ class QTCREATOR_UTILS_EXPORT TreeItem
 {
 public:
     TreeItem();
-    explicit TreeItem(const QStringList &displays);
+    explicit TreeItem(const QStringList &displays, int flags = Qt::ItemIsEnabled);
     virtual ~TreeItem();
 
     virtual TreeItem *parent() const { return m_parent; }