firefox-legacy-1.16.4.21

Change

• Prevent exceptions when several conflicting rules result in an empty filter
• Improve validation of CSS selector-based cosmetic filters
• Map upward to xpath using filter syntax converter
• Update scriptlets from the upstream repo
  • Replace requestAnimationFrame-if.js with no-requestAnimationFrame-if.js
  • Improve set-constant.js scriptlet
  • Improve window.open-defuser scriptlet
  • Add remove-class scriptlet (alias: rc)
  • Add new scriptlet to allow blocking Amazon's apstag.js
  • Bring fingerprint2.js scriptlet up to date
  • Improve logging capabilities of json-prune scriptlet
  • Add uBO: prefix to logged output in some scriptlets
• Remove obsolete filters from stock filter lists
  • hpHosts
  • Disconnect Malvertising
  • Adblock Warning Removal​

Note: The release notes are created/maintained by @JustOff.