What's Changed
* Merge changes from MicroPython v.122 release; annotate CIRCUITPY-CHANGES by dhalbert in https://github.com/adafruit/Adafruit_CircuitPython_asyncio/pull/70
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- Incorporate upstream changes, including fixing state of cur_task and other things.
- Remove ThreadSafeFlag: it's in MicroPython, but not in CPython. If we need something like this, put it back later.
- Add get_running_loop()
- Use await instead of yield.
- Restore gather to be async.
- Make comments be more CircuitPython-centric.
- Add CIRCUITPY-CHANGE annotations to note code changes from MicroPython, to ease later merges.
**Full Changelog**: https://github.com/adafruit/Adafruit_CircuitPython_asyncio/compare/1.3.5...2.0.0