Merge request of new tool docker

[Cyrille Berger Skott]

Hi,

Nice work. Just a small annoyance. Right now by default, the tool docker title 
is hidden, and if you want to move the docker around, it is problematic. I 
first tried to click on the "arrange" title, and instead it moves the window 
(well if you are using oxygen... which I don't for that reason, except for 
calligra/master), and it got me confused until I realized that you had to show 
the title before being able to move the docker. So by default, I would make 
the docker title visible, and let the user hide it if he wants.

-- 
Cyrille Berger Skott