TDB2 Merge

- Migrated TDB::merge to TDB2::merge.
- Removed obsoleted code from TDB.
- Modified unit tests for merge to use export instead of export.csv.

src/commands/CmdAdd.cpp

@@ -59,9 +59,9 @@ int CmdAdd::execute (std::string& output)
   // TODO This should be a call in to feedback.cpp.
   if (context.verbose ("new-id"))
     output = format (STRING_CMD_ADD_FEEDBACK, context.tdb2.next_id ()) + "\n";
-/*
-  context.footnote (onProjectChange (task));
-*/
+
+//  context.footnote (onProjectChange (task));
+
   context.tdb2.commit ();
   return rc;
 }