Tweaks

• Fire Aspect Lighter - idea post
• Nether Creepers
• Tree Elevator - idea post
• Tree Twerk
• Wither Flesh - idea post
• Zombie Pickaxe - idea post

Translations

• Rename en.yml to en_us.yml and add a system where the old file still works
• All messages moved from config.yml to lang files.
• Added Spanish (es-mx) translations. (thanks to @enttbot)

Other

• Refactor config implementation by moving it out of the API package.
• Created utility gradle task to make creating tweak files easier (has some issues currently).