Glass Config API

Important note: This can coexist with GCAPI2 without issues.

• Fixed many bugs, like integer configs having max length being set wrong, and a couple of crash issues.
• Config validation is now properly applied when loading from files.
• Converted to YAML instead of JSON, due to it being much easier to edit for users.
• Added the ability for modders to hide config fields from the gui.
• Many other small changes that are only really relevant to coders, which are covered in the github documentation.