Support for JSONML

[techdragon]

It would be very handy to support JSONML as its one of the new "standards" designed with the goal of handling a round trip from XML to JSON and back to XML, reliably without losing information. it seems to be the last major format from this page
http://wiki.open311.org/JSON_and_XML_Conversion/#jsonml-convention that you don't support.

More info can be found here as well - https://en.wikipedia.org/wiki/JsonML

[dagwieers]

@techdragon We accept contributions ;-)

[techdragon]

I've got a rough first draft of a version that works for JSONML, but its currently only working with the <class 'lxml.etree._Element'> objects produced by lxml.etree.fromstring() and not the <class 'xml.etree.ElementTree.Element'> objects produced by lxml.etree.ElementTree.fromstring() which you use in all your examples. So I've got a bit more work to do making it generalized to work with just the built in python ElementTree.