* Fix annotations for query parameter
* An incoming query sequence can have int variables
* Add URL.explicit_port property
* Give a friendlier error when port cant be converted to int
* bool(URL()) now returns False
* Fix annotations for build
* Fix annotations for cached_property
* Accept str subclasses in URL constructor
* Forbid inheritance, replace __init__ with __new__
* Support PEP-561 (provide type hinting marker)
OBS-URL: https://build.opensuse.org/package/show/devel:languages:python/python-yarl?expand=0&rev=22