v1.21

I've now had a couple days where I've gotten a Windows Update, and came back to the Terminal not quite in the right state as before:

• A few times, I've had the buffer restored, but to a previous day's state. As if the buffer didn't get persisted on shutdown, but on launch I did get the buffer from the previous shutdown.
• Today, I only had one of my two windows persisted across the reboot. The window that was persisted did have all it's buffers restored, but the other window was gone entirely.

I have a theory that this is somehow related to us not handling WM_ENDSESSION post-PMv3 quite right, but that's a guess, not a root cause.