This adds all dashboard changes from the last couple months.
We're about to remove the dashboard, but decided that we should
get all the recent work in first in case anyone wants to pick up this
project later on.

* cmd, dashboard, eth, p2p: send peer info to the dashboard
* dashboard: update npm packages, improve UI, rebase
* dashboard, p2p: remove println, change doc
* cmd, dashboard, eth, p2p: cleanup after review
* dashboard: send current block to the dashboard client