[style] Make toolsutils.py flake8-clean Run `autopep8 --max-line-length 100 -i cubicweb/toolsutils.py` and fixed unused imports.

[test/rset] typo

[test/rset] flake8

[py3] import configparser from six.moves instead of using a try/except Using six is better than the try/except because it clearly indicates compatibility code. Also, when using tools such as vermin which relies on AST, it helps getting rid of false compatibility errors.

[doc] didn't had any questions

[doc] missing import, cw now require this explicitely

[doc] add actual link to previous post

[doc] missing import in code example

[doc] add a note because uiprops.py is not generated anymore by default

[doc] recommend pip instead of apt for installing things According to a discussion on XMPP we should recommend pip instead.

[doc] fix, link to internal doc since it's not the blog post anymore

[doc] also show command with sqlite since it's recommended

[doc] fix, the cube name was used, it was the instance named that was needed

[doc] it's a tutorial, not a blog post anymore

[doc] make example more redable

[doc] uses :file:`name` everywhere + indicate file when it's not present

[doc] english typos

[doc] pep8/retab in code examples

[doc] correct import for i18n

[doc] pep8 and retab in tutorial code example

[doc] correct pip command to have needed dependancies to use the start command I know we want to remove this command but in the meantime having this documentation working seems like something good.

[doc] explain the difference between a relation and an attribute

[doc] plural

[doc] misc, put every reference to something in the code between backquotes

[doc] bold to make reading more obvious

[doc] style, switch to bullet points list to make things easier to read

[doc] explains what the <X.Y.Z> means

[doc] command output style has changed