• Fix a bug where include could not be nested without invalid Lua output; embed via
  package.preload to avoid repetition and referential equality issues (#214)
• Fix a bug where globals checking would mistakenly flag locals (#213)
• Fix a bug that would cause incorrect filenames in error messages (#208)
• Fix a bug causing else to emit twice in some contexts (#212)
• Dissallow naming a local the same as global in some contexts