Add an easy way to save the comments when converting to an object

[TheElectronWill]

Problem found when trying to use NightConfig for the Photon server's configuration: there is no simple way to copy all the comments (deeply) of a commented configuration. This would be very useful when converting config to object, because the conversion loses the comments.
Solution in that situation:

1. Load the commented configuration
2. Exports all its comments, including the comments of the sub-configs // needs improvement here
3. Converts it to a custom object
4. Converts the object to a config
5. Adds the previously saved comments to this config // needs improvement here
6. Save the config