[pyroboros] Subset python+pep484 for broad idiomatic transpilation.
[pyroboros] Subset python+pep484 for broad idiomatic transpilation.

jdashg/misc,jdashg/snippets,jdashg/snippets,jdashg/misc,jdashg/misc,jdashg/misc,jdashg/misc,jdashg/misc