- The order of info records with the same topic are maintained in Collection::mRecords
- The index lookup data structure are not ordered. The topic string is hashed. The infos for the topic are simply placed in a vector.
- The index values for appending or inserting a record takes prev/next values (if exist)
- FIXME: prev/next values are not adjusted for adding or removing records
- FIXME: undo after reordering does not reset the modified flag
(copied the changes from commit SHA-1: 06f9922822)
