std.data.json formal review

[Martin Nowak via Digitalmars-d]

Will try to convert a piece of code I wrote a few days ago.
https://github.com/MartinNowak/rabbitmq-munin/blob/48c3e7451dec0dcb2b6dccbb9b4230b224e2e647/src/app.d
Right now working with json for trivial stuff is a pain.