DeepLink dot graph improvements

[sinelaw]

This issue is about ideas to improve the graph output.

Currently the data is partial, arbitrarily including dependencies only the first time they are encountered.
This is arguably better than including all possible paths, because the graph would quickly become huge.

Alternatives:

1. Include all possible paths (very ugly)
2. Include only the deepest path (from root) to each node. May be misleading if there are "more important" (subjectively) paths that are shorter.
3. Cluster big groups of shared dependencies and point to them from multiple dependents.
4. ???

[ElastiLotem]

1. PageRank algorithm on the graph? (probably a silly idea :-) )
2. like 2 plus coloring scheme / label indicating how many more hidden dep paths it has?