Fix typo on documentation in 'hacking'.
Change bullet list to enumerate list.
Fix PEP8 for libqtile. Almost done
Clean of the huge if statement in 'command'. Need to go deeper and
simplify it.
Code reducing on 'display' assignment.
Thanks to xarvh.

code reducing thanks to xarvh

No need to check if 'r' is None (already checked in _items() and more
explicit names for r (thanks xarvh).

About the '\' I guess it depends on the style.
Final fix PEP8 for libqtile. All PEP8 tests pass excepted doc lines (> 79 characters) in config.py. (More pythonesc loop and idents fixes too).
Fix PEP8 for layouts. All PEP8 tests pass excepted doc lines (> 79 characters) in ratiotile.py.
Fix PEP8 for resources. All PEP8 tests pass.
Fix PEP8 for widget. All PEP8 tests pass excepted doc lines (> 79 characters) in maildir.py and mpdwidget.py.