title: Can the PDB module of Biopython handle CONECT records
body: <p>I'm investigating using biopython to process PDB files, but it looks to me like the CONECT records are not handled. For instance, I'm wanting to use it to extract a ligand from a PDB  structure, and I'm getting the atoms (HETATM) written but the corresponding CONECT records are lost. Is there a way to include these?</p>