except critical parameters:
- simple switch handled
- switch with string/number argument handled
- switch with url/path/basename argument handled by giving data

/reviewed-on !6

that can happen on the environment where UNO library is built with Python 2.

/cc @rafael @gabriel @kazuhiko 

/reviewed-on !5

unnecessary space change removed

So that both readme and changelog automatically render well on

https://lab.nexedi.com/nexedi/cloudooo  and on  
https://github.com/Nexedi/cloudooo

CHANGES is also renamed -> CHANGELOG along the way, because that's what
gitlab autodetects as changelog file name:

https://lab.nexedi.com/nexedi/gitlab-ce/blob/827d3914/app/models/repository.rb#L353

/cc @kazuhiko, @gabriel

/reviewed-on nexedi/cloudooo!3

writer_png_Export filter now works but draw_eps_Export and impress_eps_Export do not work.

also remove filters that now work from default black list.

also keep backward compatibility with a whitespace separated string that is provided by old ERP5 code.

that prevents detecting the end of unit test.