ADDED: Cached copy of edges.json to use if local CreeperHost node is inaccessible
ADDED: Select a random server on startup to use for 'Automatic' if the local CreeperHost node is inaccessible
ADDED: If fetching edges.json failed, test each mirror in the cached list to make sure it's online
ADDED: Console error message for when no servers could be accessed
CHANGED: Removed Chicago from cached edges.json
ADDED: Extra logging for server failures
Merge pull request #667 from Viper-7/master

edges.json fallback