Next

This is almost exactly the same as #395 except:

 * we now merge a dev branch into master (0.7.0 is released and master is opened again)
 * commit (and messages) are clearer, cleaner, fewer, simpler (genuine thanks go to @wking for forcing me into a better engineer to collaborate with :-))
 * requirements are regrouped and put inside a folder (cleaner root), following @wking suggestion
 * wording for documentation is better, clearer (@wking)
 * bumped the package version so that someone running from master clearly reports the next to come version, and not the currently released one

@samalba already LGTM-ed #395 so that should merge relatively fast, but please (@shin- @wking) take a moment to get over this.