Widget to produce code for embedded datasets

Added  the widget views and a basic interecation  for the dataset embedded.

The file "plugin.py" was changed for add a directory "fanstatic" and
ensure a correct style including the static file in "page.html".

![embedded-datamx](https://cloud.githubusercontent.com/assets/660973/4105994/00d14856-31b4-11e4-9521-647fc1378fb1.png)