WIP: equality comparisons for GenNode

forwarding equality to the embedded EntryID
Basically, two GenNodes are equal when they have the same "identity"
Ironically, this is the usual twist with database entities

src/lib/diff/gen-node.hpp

@@ -184,6 +184,9 @@ namespace diff{
           // standard copy operations acceptable
         };
       
+      
+      //------GenNode Data fields---
+      
       ID      idi;
       DataCap data;
       
@@ -232,6 +235,19 @@ namespace diff{
         return node.idi.getSym();
       }
       
+      friend bool
+      operator== (GenNode const& n1, GenNode const& n2)
+      {
+        return n1.idi == n2.idi;
+      }
+      
+      friend bool
+      operator!= (GenNode const& n1, GenNode const& n2)
+      {
+        return n1.idi != n2.idi;
+      }
+      
+      
     private:
       template<typename X>
       static string