macOS 10.8 not starting reliably

The virtual machine with macOS 10.8 is not always starting up reliably. The symptom is that it hangs on the graphical start-up screen. The cause is unknown. A hard reboot makes it come up subsequently.

It appears to only affect 10.8 - we should consider working around this in coin via an agent timeout and machine power-cycle (not realloc), similar to what we've had in vsphere.