Reformat docstring for pep8 line length
Fix debian_service.get_all() to check all of /etc/init.d
Remove README from debian_service get_all()
Use set union instead of + to add two sets
Fix debian_service.get_disabled to subtract enabled from all
Merge pull request #3746 from basepi/fix_debian_services

Fixes #3497 Overhaul debian_service.py system