Qbs: Show products in simplified project tree

So far the simplified project tree was a flat list of files for qbs
projects. With this change it is a flat list of Products, each
containing a flat list of all files referrenced.

Change-Id: If53e80ca69f595df245a20af9f9ced1121cf30af
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

src/plugins/qbsprojectmanager/qbsnodes.cpp

@@ -256,9 +256,6 @@ QbsBaseProjectNode::QbsBaseProjectNode(const QString &path) :
 
 bool QbsBaseProjectNode::hasBuildTargets() const
 {
-    foreach (ProjectNode *n, subProjectNodes())
-        if (n->hasBuildTargets())
-            return true;
     return false;
 }
 
@@ -486,6 +483,11 @@ bool QbsProductNode::isEnabled() const
     return m_qbsProductData.isEnabled();
 }
 
+bool QbsProductNode::hasBuildTargets() const
+{
+    return true;
+}
+
 void QbsProductNode::setQbsProductData(const qbs::ProductData prd)
 {
     if (m_qbsProductData == prd)