Layering:

File format: BIRD OSPF style
	TODO: spec
		- Two sublayers: syntax, semantics (what attributes are defined for what)
	Ref: BIRD's source code?

Parsing layer: create own objects from the OSPF state dump.
	FIXME: currently does not exist and everything is ugly

Graph layer: get two maps: ref and current
	compare using some dicts, probably
	Output: the graph, differences between maps

Visualisation:
	Vertex and edge positions and styling
	Network reduction (TODO: here or before?)
	TODO: File format: use BIRD style, or something else
		- We need to be able to write this
	Underlays
	Interactions (SPOFs, trees, path finding)
	Map editing mode