chore(ConfigManager): ConfigManager refactoring

So, initially i just wanted to add ability for `start` method to redefine port number in config and for config manager functions to use other config values, so this resulted in this refactoring. 
Now, we have ConfigManager which  exports only one method - the manager function itself, it accepts raw config object and returns new one with default values. ConfigManager has a list of default values factories which accept user defined value and can access other config properties as well. Configuration was moved to the `start` method.
Also I think it makes sense to unify config properties names, because for instance we have passport properties in ALL_CAPS and all other properties in camelCase, and I decided to use ALL_CAPS since it is usually chosen for constants and configuration variables. So, I've started renaming, but I only renamed those properties that used in kernel without touching plugins, so that this update should be more or less atomic.