* Add 'Output.all' combinator for Python
Output.all is a useful combinator that we already have in Node that
allows the composition of a list of outputs into an output of a list.
This is very useful when authoring components and its lack of presence
in Python was an oversight.
This commit adds 'Output.all' and 'Output.from_input', adding tests and
documentation for each.
* start unwrap
* Add functionality and test for nested inputs