launcher missing shutdown logs on Windows

[RebeccaMahany]

Oftentimes on Windows we miss all of launcher's shutdown logs -- e.g. going right from regular launcher logs to a gap of a couple seconds, then launching service and windows service starting. There's nothing illuminating in the event logs, either. This makes it really tough to figure out why launcher is shutting down unexpectedly.

We should get logs about rungroups shutting down, or goroutines panicking, or the service shutting down. It is not clear to me why these logs are missing.