fix memory problem in cif::item, making it safer

start branch code in model::structure (not done yet)

reverted to returning empty results in case nothing is found

changed find1 logic for only row_handles, now returns empty row_handle instead of throwing when not found
various condition fixes

fix get_parents_condition

Implemented reorder by index

file constructor from raw data

fix dangling memory reference

- fix dssp TCO value