No protocol slap fights in the docs

This patch removes a long standing irksome bit in the JSON::XS docs.  This protocol slap fight is of no use to the user and has no place in module documentation.  Only the bits which are relevant to the user have been left in.

If YAML compatibility is a practical concern, write an "as_yaml" method to work around the problems.  Far more useful to the user than carefully enumerating the minute problems.

I also cleaned up a handful of overly chatty bits of the docs and references to "I".