AltStable Companion v0.1.0-beta.2

The beta that can update itself: this is the last one you download by hand.

Added

• An About section under Help: the version and build this is, what the app is, and links
  to the project, its issues page (for reports; Open log is beside it), the addon, the
  licence and Blizzard's trademark terms. The browser opens them.
• Check for updates, under About: the app asks GitHub for the list of releases and
  says whether a newer one exists. Update now downloads it beside the running file and
  checks it against the release's SHA256SUMS; Restart now finishes the portraits in
  hand, puts the new file in place of the old one (kept as .old until the next start) and
  starts it. A beta sees betas and releases; a release sees only releases.
• A Settings box, off by default: Check for updates when the window opens (at most once
  an hour). A download is always a button press.