Add: tensor.choose and typed_list.make_list

This is a rebase and a completion of PR gh-1983

Newt.txt:
- Add tensor.choose as numpy.choose (Jeremie Tanguay, Frederic B.)
- Add typed_list.make_list (Jeremie Tanguay, Frederic B.)
Most of the Ops actually have docstrings, either in the Op class, or in the user-facing function that is decorated with `@constructor`. Here, neither have documentation, which mean that calling `help(choose)` (or `choose?` in iPython) will not return anything useful.