network tracing

[rade]

Scope can help making analysis of network / service issues easier by facilitating the tracing of network traffic. e.g.

• click on a node (container/service/...) and automatically fire up wireshark showing all the traffic going to that node
• click on an edge and automatically fire up wireshark showing all traffic going across that edge

Note that for compound nodes, e.g. services, per-image nodes, etc, this requires trace aggregation, though we can perhaps leave that out initially.