Parsexml script for creating courses added

The script is added in ndf/management/commands and can be run from terminal with python manage.py parsexml

It fetches the course content from exported course directory from edX and creates pages and modules in metastudio accordingly

The installation and documentation instructions can be found at the [metastudio file link] (http://www.metastudio.org/gLite/file/53c618e17d9d332fb1abda6b)