Community discovery

[grimadas]

We need a simple crawler to discover which communities there are in BAMI.

[devos50]

The crawler should also join any community it discovers, and fetch the full community DAG. This will tremendously help to monitor the network health and discover anomalies in our live overlay.

[grimadas]

I see at least three different modes:

• Full sync - download the full chain of the community
• Last state - get last state of the community
• Id and meta-data only - get only id of the community (only to get how many peers/communities there are)