Comment 17 for bug 1371454

Ok so the issue is the ~Signal() is being called from withing the Signal executor...so recursively acquiring the same lock.

An async execution of the code that ends up deleting the PlayerImplentation solves that issue and avoids hangs in the unity8 autopilot tests.

There's still an issue where ocassionally ~PlayerStub (during unity8 stop) hangs waiting for the dbus worker thread to finish; however that doesn't cause the autopilot tests to hang as the unity8 process is eventually sigkilled if that's the case.