Add date to release notes.
fix repeated list multiplication

--HG--
extra : amend_source : 2797e0ad678cc0a33a2548a8a20b00475bc8a21b

Conflicts:
	CHANGES.rst
Merge branch 'master' into 0.20.x

Conflicts:
	CHANGES.rst
0.20.1rc1
Bump version for release.
Merge branch 'master' of github.com:cython/cython
Bump version.