0.9.0

Select all results, plugin settings, security, more server settings

• Selection mode: "Select all N results" across unloaded pages (ids only)
• Plugins: edit each plugin's settings
• Security: set/change/remove username and password (the TV signs in
  again), make a new API key
• More server settings built from Stash's schema: paths and files,
  previews and sprites, web interface, scraping, log settings, session
  length; DLNA settings and start/stop; log viewer; database backup and
  optimise
• Update README; bump version to 0.9.0