Rendering and AbML for camelids

[AndrewCRMartin]

Related to #18 issue: Having displayed

VHH.a(1:5){1}-H(2:6){2}-CH2(3:7)-CH3(4:8)|VHH.a(5:1){1}-H(6:2){2}-CH2(7:3)-CH3(8:4)

if one clicks Get AbML or Tidy, one loses the interaction 1and disulphide between the VHH domains:

VHH.a(1)-H(2:6){2}-CH2(3:7)-CH3(4:8)|VHH.a(5)-H(6:2){2}-CH2(7:3)-CH3(8:4)

This is not urgent at all, but it is quite common for people to indicate the 3rd disulphide in a camelid structure between the two VHH domains instead of in the hinge, yet still draw it with the Y-shape. I know that creates problems for the drawing program knowing that these are interacting, so it might be easier to allow camelids to be drawn with the VHHs touching.

[JamesSweetJones]

From now, when the Camelid antibody is drawn, the VHH domains are within range that they may interact, however, this interaction is only notated in the AbML when there is a disulphide bond between the two domains.

[AndrewCRMartin]

Really nice!