Improve configuration management for multiple servers

[reck1610]

What is the issue, e.g. map voting, you would like to solve?

It is tedious to manage configurations for multiple squad servers and keep them in sync.

How would you like us to solve this issue?

I would like SquadJS to allow multiple configuration to be loaded.
The configurations should be passed as additional parameters like this:

node index.js config.base.json config.server1.json

The configurations should be deep merged. Changes in later configurations should overwrite earlier configurations.
Arrays should be concatenated object properties should be replaced.