v2.31.1: Saved tokens stay with their own stack, more secrets hidden, and safer stack and update handling

• Your saved token only goes to its own stack. Pointing MERIDIAN_FQDN at another address no
  longer sends it there, and stacks move accepts only the stack's own new address unless you
  confirm another, with certificate checks on.
• Connector credentials are harder to expose. Messages and errors hide more secrets, such as
  quoted passwords, client secrets and AWS key ids, and raw API requests can't reach credentials
  via a redirect or another spelling of an address.
• Safer stacks and updates. A damaged stacks file stops the skill instead of being saved over,
  switching stacks keeps machine-wide settings such as a proxy certificate, and self-update never
  installs an older version, even when forced.
• Quicker failures and sturdier reports. A failed request reports straight away instead of
  waiting 2 seconds first, PDF reports work in folders with # in the name, and Slack alerts no
  longer expand link previews.