Log information about entering and leaving device scope
I was running some rendering examples and I was surprised to
see some log messages stating that my device was being forced
to Serial. Panicked, I opened up a debugger and set a breakpoint
where the device was forced to Serial. Turns out, the device
was forced to Serial inside of a ScopedRuntimeDeviceTracker
(as part of the ColorTable operation). However, the log
gave no indication that the default devices were restored.
To prevent further misunderstandings for myself and others,
added some log messages to the ScopedRuntimeDeviceTracker
to write when the scope is entered and left at the same logging
level as that of the announcement that the device is forced.