fix: Allow ';' in PathNameValue; Make XML collection less strict

[airween]

There are two modifications which fix the phpbb plugin issue:

• PathNameValue must have been extended, because it's used to reduce as @beginsWith for eg., and the ; needed
• XML is represented as SpecialCollection, and it was too strict: it allowed only the collection with key, but the exclusion contains only the collection name (XML)

The parser became less strict with these modifications.

CRS (the current) is still parsed as well.

[airween]

Sorry, I didn't realize that there were an uncommitted modification: REQUEST_BODY_LENGTH and REQUEST_BODY variables were reordered, because the first one (body length) is longer and the other is a real subset of this, so the longer one should be first.