This code is originally written (with much thanks) by
@mikenerone:matrix.org. Adds a `tractor.trionics.ipython_embed()` which
is `trio` compatible and allows straight up `await async_func()` calls
in the REPL with expected default blocking semantics. More refinements
to come including user config loading and eventually a foundation for
what will be a console REPL + %magics for shipping work off to actor
clusters and manual respawn controls and thus probably eventually
obsoleting all the "parallel" stuff built into `ipython` B)
Probably pertains to #130
7f65d80b56