Optimization

- TDB::load can entirely skip the loading of completed.data if the
  specified filter is just so.
- Added FEATURE_TDB_OPT definition to allow disabling of this.

src/main.h

@@ -25,6 +25,10 @@
 //
 ////////////////////////////////////////////////////////////////////////////////
 
+// TDB Optimization attempts to reduce the amount of I/O.
+#define FEATURE_TDB_OPT 1
+
+
 #include <string>
 #include <vector>
 #include <map>