Integration of "arrows" ad "neovis", persistent visual properties of logical attributes

[saliez]

At one side "arrows" is very easy to manage parameters of nodes and relationships, like size, thickness, colour, ... although only for individual cases of the current node or edge. At the other side in "neovis" the value of a parameter can control the appearance of all nodes and relations having this specific parameter or type. A persistent table should convert logical attributes of a project into the associated visual aspect. For example if a relation has an attribute meaning high importance this edge should always looks thicker. Or if a node has a type meaning "Problem" this node should always appear in red. The relative priority of this Problem could be represented by the size of these nodes.