Added TaskGroup.start_soon() and changed spawn() back into a coroutine function

[agronholm]

One more step towards a trio-like API.

[agronholm]

This will break code written against the release candidates. The fix should be easy though.

[agronholm]

I'm only just wondering if we could emit deprecation warnings from the renamed methods. How would AnyIO 2/3 compatible code look like?

[smurfix]

Why doesn't spawn emit a DeprecationWarning?

[agronholm]

I'm trying to give library developers a way to use AnyIO 2.x and 3.x in the same code base without running into deprecation warnings. With free functions you could just conditionally import them but with methods it's not as simple. Can you suggest a solution?

[smurfix]

Hmm. Tricky, sounds like "defer adding a deprecation warning to spawn until anyio 3.1" is the best (or at least easiest-to-implement) idea here.

[agronholm]

I made them emit deprecation warnings after all, and pointed out that cross-compatible code could simply suppress the deprecation warnings. Good enough?

[smurfix]

Perfect.

[agronholm]

Thanks for the review!