Added ioam submodules

Includes:

doc/extensions on ioam-builder:docextensions
doc/nbpublisher on ioam/ioam-builder:nbpublisher
doc/reference_data on ioam/ioam.github.com:featuremapper-data
dataviews on ioam/dataviews:master
imagen on ioam/imagen:master
param on ioam/param:master
Initial commit of the Sphinx documentation