RFE: make "interfaces" command smarter about glycosylations

[Elaine Meng]

When I open 4n5z and enter "interfaces #1" it makes tiny disconnected dots in the diagram for all of the glycosylation "chains" due to the unfortunate way that wwPDB decided to incorporate those things. They aren't really separate chains since they're bonded to the protein. Diagram image is attached to this ticket.

However, I consider this fairly low priority since it can be avoided if the user knows to specify only protein in the command, e.g. "interfaces protein". Still I wonder if there is some easily accessible magic to avoid treating them as real chains. Maybe "log chains" uses such magic, see second image attached to this ticket.

[Elaine Meng]

Eric said earlier via e-mail: I don't know what logic you're using to include glycans but not, say, solvent, but I think what you want to do is restrict it to residues whose 'chain' attribute is not None.