Pick a JSON library and expose some convenience functions

[danielsuo]

Some options:

• http://www.digip.org/jansson/
• http://zserge.com/jsmn.html (probably too simple / not performant)
• https://github.com/json-c/json-c
• https://github.com/kgabis/parson
• https://github.com/udp/json-parser

[ghost]

json-c is pretty good for the task in hand.