Add edges.go for working with node connections

This will eventually be used to draw lines (edges) between known nodes
on the physical map.
Implement CJDNS-specific Network type

This also adds a bunch of debug code, which needs to be removed in the
future.
Put together demo API endpoint for known peers
Display connections between nodes on map
Flatten peers data structure and update peers.js
Remove unused arguments in peers.js
Ensure that peering data is refreshed on heartbeat
Add example NetworkAdmin block in configuration
Merge branch 'f.edges'

* f.edges:
  Add example NetworkAdmin block in configuration
  Ensure that peering data is refreshed on heartbeat
  Remove unused arguments in peers.js
  Flatten peers data structure and update peers.js
  Display connections between nodes on map
  Put together demo API endpoint for known peers
  Implement CJDNS-specific Network type
  Add edges.go for working with node connections