Import jsoncpp-0.6.0rc2nb20140418 as wip/jsoncpp-svn.

JSON (JavaScript Object Notation) is a lightweight data-interchange
format.  It can represent integer, real number, string, an ordered
sequence of value, and a collection of name/value pairs.

JsonCpp is a simple API to manipulate JSON value, handle serialization
and unserialization to string.

It can also preserve existing comment in unserialization/serialization
steps, making it a convenient format to store user input files.

Unserialization parsing is user friendly and provides precise error
reports.
+ jsoncpp-svn