Replace TransportConfig with namespaced Settings
The Tor and Bluetooth plugins use a mixture of Settings and TransportConfig to store their configuration. No other plugins use TransportConfig.
Add namespaces to Settings so all components can use them without treading on each other's toes, and remove TransportConfig.
Plugins should be able to access their settings through the PluginCallback, as they currently can for TransportConfig. Perhaps the PluginManager should also push updated settings to the plugins so they don't have to listen on the EventBus?