Support writing output in JData (JSON and UBJSON) and JNIfTI format

[fangq]

JData specification defines a portable and lightweight data annotation approach that allow flexible storage of typed and binary data in JSON and binary JSON-like constructs. The output file is human readable, and widely supported in many applications.

JNIfTI is a JSON/JData wrapper for the widely used NIfTI-1/2 format. It allows easy parsing and internal data compression, making NIfTI file readable, searchable and easy to be integrated with other complex metadata.

We will allow MCX to write the volumetric output int he format of JNIfTI (which follows the JData specification as the annotation format, and JSON/UBJSON as the serialization format).