Douglas authored Jun 20, 2016 and Ivan Tyagov committed Jul 11, 2016

@Tyagov this is the slapos part of nexedi/erp5!131. It includes:

- Documentation on top on each Jupyter notebook about why and how we use the
environment object.

- astor egg, used to convert abstract syntax tree objects back to source
code.

/reviewed-on nexedi/slapos!76