TDB2 - Diagnostics

- Added a diagnostic dump of the TDB2 state in debug mode.
- Added a call to TDB2::dump at the start of TDB2::commit.
- Removed unnecessary calls to TDB2::dump.

src/Context.cpp

@@ -153,7 +153,6 @@ int Context::initialize (int argc, const char** argv)
     tdb.clear ();                   // TODO Obsolete
     tdb.location (data_dir);        // TODO Obsolete
     tdb2.set_location (data_dir);
-    tdb2.dump ();
 
     // Hook system init, plus post-start event occurring at the first possible
     // moment after hook initialization.