biblatex type to genre, number to serial for non-article.

[cgevans]

This is meant to close #295 :

The type field (not entry type) in biblatex is used to set genre, regardless of entry type. I think this is appropriate for all uses of type; biblatex's documentation states type is "The type of a manual, patent, report, or thesis. This field may also be useful for the custom types listed in § 2.1.3.", while Hayagriva's file format states genre is "Type, class, or subtype of the item (e.g. "Doctoral dissertation" for a PhD thesis; "NIH Publication" for an NIH technical report). Do not use for topical descriptions or categories (e.g. "adventure" for an adventure movie).".

The number field is more of a problem. Biblatex's documentation describes it as "The number of a journal or the volume/number of a book in a series." However, it then goes on to say "With @patent entries, this is the number or record token of a patent or patent request", and, not documented in the description of number, is listed as an optional field in several entry types that seem more likely to be using it as a CSL number / Hayagriva serial-number than an issue number, namely report, manual, and dataset. So I'm not quite sure what the best handling here is.

I've done what seems to be to be the minimal change, which is to set serial-number for Repository, Reference, Patent, and Report, the Hayagriva types corresponding to the biblatex types that list number as an optional field where serial-number seems to make more sense. But I wonder whether non-default styles also use it for other types, eg, Manuscript, Thesis, etc?

[cgevans]

Test failures appear unrelated here.