Revert "Merge pull request #100 from glarizza/tickets/2.7.x/9192_launchd_fix"

This merge, along with the merge for pull #99 has 11 failing tests in
spec/unit/provider/system/launchd_spec.rb, reverting commit/merge until
resolved.

This reverts commit 2828d22daef9996a94e08a3942f2bf85bdb5c7a0, reversing
changes made to 74cffa087aa35d31b331033870b026d41e40cb07.