Some instances of outdated spec text

[larsgw]

There are a number of places where the specification is unclear about or inconsistent with what people are expected to do, and I think it would be a good idea to canonicalize those deviations.

• the significance of the order of cs:label in cs:names: see this post
• the meaning of genre and medium: see this post
• descriptions for the variables container & original-author
• clarification that a variable suppressed by cs:substitute is considered empty for the purposes of determining whether to suppress the enclosing cs:group (that's what citeproc-js does, anyway)

[larsgw]

Found one more:

• how cs:group and cs:macro should behave in case of empty variables: see this post

[bwiernik]

For original-author, I suggest this text: The original creator of a work (e.g., the original songwriter or performer for a musical piece; the original developer or programmer for a piece of software; the original author of an adapted work such as a book adapted into a screenplay)

container should probably be deprecated (or at least not classified as a date). The spec text should just indicate that it should not be used, instead of "?".

[bwiernik]

These will all be resolved by open pull requests.