Add option to force JSON5 for patch files

[rhullah]

Some mod authors use comments in their .json config files. This prevents the use of patching values as comments are not part of the standard JSON specification. Add an option to allow comments even though the source is JSON.

[itzg]

I forgot to mention that the latest image now includes this and $add support for patch operations.

[rhullah]

Awesome thanks! I'm just now getting around to try this. It looks like I need to set the environment variable PATCH_JSON_ALLOW_COMMENTS to true. Is that correct? If so, that doesn't seem to be allowing comments.

[itzg]

Had missed the important line of code that connects the new option to the patch set processor.