Enforce unambiguous case

[kriskowal]

Across languages, any identifier may be remapped from PascalCase or camelCase to a convention acceptable for an identifier class in its particular language. For example, Python remaps camelCase methods to snake_case. Go must remap camelCase to PascalCase on methods for them to be public. As a consequence, no name space can have two names that vary only by their case convention. This needs to be enforced to guarantee portability.