systat 0.1.1

• systat updates itself. Once a day it asks GitHub for the latest release, and when there is a newer one the panel shows Update to systat X:
  • the download is checked against the release's SHA-256, and the new app must be systat at the release's version, notarized and signed by the same developer as the running one
  • the disk image must be signed by the same developer before it's opened, and Gatekeeper must accept the new app, which also checks the certificate hasn't been revoked
  • the old app is moved aside, not deleted, and is put back if the new one doesn't verify; if that happens, the panel says why the next time it offers the update
  • one update at a time, even if one is started from the panel and another from a terminal
  • it won't update itself in a folder other users can change, such as /Users/Shared, or on a drive that ignores ownership, and it only reopens an app that passes the same checks
• Settings has a switch for the daily check and a Check Now button.
• systat --update installs the newest release from a terminal, and systat --check-update only asks.
• 0.1.0 has no updater: update from it once with the installer command in the README.