flake8 --select W391,E302,E301,E304

autopep8 can't fix W391 even though it claims it can.
Fixed using a simple custom script.

Signed-off-by: Pierre Mazière <pierre.maziere@gmx.com>

Signed-off-by: Roger Philibert <roger.philibert@gmail.com>

Remove useless trailing \
Remove trailing spaces
Add missing empty lines

autopep8 -ir -j2 --select=E301,E302,E502,W291,W293,W391 .

Diff quickly checked.