Multidict

Fixes another memory leak introduced by 4.5.0 release.

aiohttp client API leaked memory with multidict 4.5.0-4.5.1, the release fixes it.

Changes
------------

* Fix another memory leak introduced by 4.5.0 release 307

The release fixes a very serious memory leak introduced by 4.5.0 release.

Upgrade from 4.5.0 to 4.5.1 is highly recommended.

Changes
------------

* Fix a memory leak introduced by 4.5.0 release 306

------------------

* Multidict views ported from Cython to C extension (275)

Changes
-------------

* Restore Python 3.4 support (289)

Changes
-------------

* Fix type annotations (283)

* Allow to install the library on systems without compilation toolset
(281)

Changes
-------------

* Fix pep 484 stub file