Rename LoggingSystem.bootstrap to ConsoleLogger.bootstrap

[fpseverino]

As @czechboy0 said:

[...] now that ConsoleKit uses Swift Configuration, I think this should be renamed to something Vapor/ConsoleKit-specific: LoggingSystem.bootstrap(config: ConfigReader). As this is API that could presumably be added to Swift Log/Swift Configuration themselves, it's kind of similar to the retroactive conformance feature.

Eg ConsoleLogger.bootstrap(config:) or something would be fine.

I have renamed it according to the above suggestion. If anyone has any other ideas, please let me know!