Add special value for the spinbox.

The spinbox is not accessible directly, a hack is needed.
Merge branch 'master' of https://github.com/blink1073/spyder_autopep8

Conflicts:
	p_autopep8.py
Remove deprecated warning in readme
Add icon to action

Fixes gh-9
pep8
Comments
Lower description indent
Reorganize layout code
Improve description position
Refactored to use minimal Plugin interface