Get this remove/re-add dance finally sorted out for good

Change-Id: I16cb3fdd699dcd45de25b49d30e0d1b6392fd82b

configmgr/source/modifications.hxx

@@ -24,8 +24,9 @@
 
 #include <boost/unordered_map.hpp>
 
-#include "path.hxx"
+#include <config_dconf.h>
 
+#include "path.hxx"
 
 namespace configmgr {
 
@@ -45,6 +46,10 @@ public:
 
     void remove(Path const & path);
 
+#if ENABLE_DCONF
+    void clear() { root_.children.clear(); }
+#endif
+
     bool empty() const { return root_.children.empty(); }
 
     Node const & getRoot() const { return root_;}