Recognize JSON and XML by media type suffixes

[scop]

Moved the XML match to after HTML with the assumption that these are processed in order, so that application/xhtml+xml still gets treated as HTML. It seems to for me in bat, but I haven't researched if that's guaranteed to be the case.

The regexps for suffix matching aren't that strict re the main type and beginning of the subtype, so they could match some invalid types. But I guess this would be ok for practical purposes.

[keith-hall]

can you give some real-world examples of media types which are not currently matched but will be after these changes, please? :)

[scop]

Searching for +xml and +json at https://www.iana.org/assignments/media-types/ gives an overview of such types. The ones immediately springing to mind for me at the moment are image/svg+xml, application/merge-patch+json and application/problem+json.

[keith-hall]

Thanks! Btw, do you want your name in the credits somewhere? as you are a great help with testing and making improvements :)