highlight central node by default

[vw253]

For the graphs centred on a specific gene, like cdc2

http://www.esyn.org/dev/builder.php?type=Graph&query=SPBC11B10.09&organism=4896&interactionType=any&source=pombase

it would be useful if cdc2 were highlighted so that the "add interactions" menu were immediatly visible

[Giorgio Favrin]

For this we would need to have something ad hoc for these type of networks - and I don't think its a priority at the moment .. this should be marked very low priority