0.10.0

set up and upgrade Stash servers from the TV, grouped web UI options

• Connecting to a new Stash opens a setup panel (settings file, library
  folders browsed on the server, database/generated/cache/covers
  locations) and offers a first scan
• A database from an older Stash can be upgraded from the TV (backup first)
• Schema-built settings panels handle grouped options (image lightbox,
  disable dropdown create)
• Settings → Stash server: check for Stash updates
• Clearer empty-library hint; update README; bump version to 0.10.0