[Cython] Cython 0.27 alpha 1 is available

[Stefan Behnel]

Hi all,

Cython 0.27 is nearing completion, so here's an alpha release to get
feedback on the many new feature that went in.

https://github.com/cython/cython/archive/0.27a1.tar.gz

These are the major new features:

- PEP 484/526 annotation typing
- PEP 525/530 async generators
- automatic "__richcmp__()" generation from "__eq__()" & friends
- support for Python object references in C++ classes
- PGO compilation mode in Jupyter notebooks

Plus many little enhancements and bug fixes. For a longer list of
improvements, see the changelog:

https://github.com/cython/cython/blob/2c9641a749208dbc405209e367b8a23e1310564d/CHANGES.rst

Hope you like it. The timeframe for the final release is hopefully early
October. The more feedback we get, the quicker we can prepare it.

Stefan