User node selection/reporting improvement suggestions

[hal0x2328]

The new version of Neon has been well-received but still has minor issues with users experiencing
node issues as if they were Neon issues. Neon should have a very clear indicator on the dashboard
of the current node that is being used, and perhaps a health indicator for that node as well.

Also, while users can manually select a node during times of network issues, it may cause a later
problem if that node gets behind or starts experiencing latency - the user must continually remember to go back to settings to select another node or go back to automatic mode - IMHO the node selection widget should be accessible directly from the dashboard.

Finally, sorting nodes by block height and ping time combined may not be the best approach - I think
the list should prefer block height over ping time, with limits for both. Since the list only shows the
"top 15" nodes, it causes out-of-date nodes to block out current nodes from being selected simply because the out-of-date nodes have less latency in responding.