Use exec to control Bluetooth state

The property_list_key module is causing some problems for my boxen
across multiple versions of OSX so I'm switching these all to exec
commands. I'd rather if I didn't have to but unfortunately I can't
devote any more time to troubleshooting the property_list_key bugs.
Removing plist module

This is causing some problems on Mavericks and I am trying to simplify.
I'll just write everything with exec commands.
Merge branch 'plist-strip'