update 19.6.0 changelog

add changelog

releae often shoudl be our mantra. We have too much fixes in that release that
were waiting since a while. Let's start a month release (ore more) from now.

keep a consistent style

it should be 19.4.4

bump to 19.4.3

fix typo

document change

encode fix test

fix typo

bump to 19.2.1