Csv report export

This partially addresses #525 and #254.  I would like this pull request to be prioritized for review, so that Mpilonhle could have an early release to suit their needs.

Background:
Many people need to combine KA Lite data with other data, such as administrative reports or paper-based tests.  We need to allow exporting of data, to facilitate this.  

Issues:
At this moment, one of our early partners (Mpilonhle) is requesting this feature.  

Changes:
* I have implemented a simple version that addresses their needs, and provides a framework for future iterations.
* In doing so, I reorganized code such that:
    * All of our app-specific decorators have moved into the "shared" folder.
    * All of our generic "internet" functionality (Json/JsonP/urls) has been localized to the "utils/internet" module.