Revert "Final pep8 fixes"

This reverts commit serverdensity/python-daemon@00a6cff357340a8cc8f21a4888b88777a5a524a3.
Moved shutdown handlers definition outside for extensibility.
Pseudo cherry-pick from mrares/python-daemon@07a7f2de3d386b6630ef34a0138cb335cfaf6ed2.