DBBrowserDB: Remove the dirty flag

Remove the dirty flag as it is no longer needed. Because we track the
savepoints currently held open we can just use that list to see wether
there are changes to be committed. So there is no need to track this in
a separate variable.

src/EditTableDialog.cpp

@@ -107,7 +107,6 @@ void EditTableDialog::accept()
     if(m_bNewTable)
     {
         // Creation of new table
-        // we commit immediatly so no need to setdirty
         if(!pdb->executeSQL(m_table.sql()))
         {
             QMessageBox::warning(