node info

[boyska]

A node could want to specify metadata about itself.

• a name: this will be displayed in many places (tipycally, where Libreant is now shown)
• a geographical position: this will be useful for opensearch

Maybe more. I propose to call these options with a NODE_ prefix: NODE_NAME, NODE_GEO, etc.

This is useful for:

• branding!
• agherant, so that aggregator can know more things about the node it's aggregating