0.8.12
- Implemented mdb_set_compare and mdb_set_dupsort
- Implemented cursor operations: multiple put, get multiple, move next multiple
- DatabaseOpenFlags.DuplicatesFixed now include DuplicatesSort by default
- MoveNextDuplicate and MovePrevDuplicate now return only value
- Actualised CursorPutOptions and PutOptions
- Added missing to-bytes converters
- API improvements and changes