1.2.8

Say it out loud when an update did not install

The updater works after the window is gone, so anything that stops it — an
antivirus eating the copy, PowerShell closed by policy, a damaged archive —
looked to the user like "pressed yes, the program closed, and that was it".
Leave a note with the version we expect before quitting and read it on the next
start: if the running version is not the one we waited for, say so, point at the
updater log and at the release page.