v1.5.39

• Circumvent CSP on AMO and other https sites in Firefox
• Add a global Test button for all regexps of the style. Clicking a regexp focuses its element.
• Show progress in popup when downloading style search index
• Fix csslint for tag selectors in nested CSS per the newest spec
• Fix csslint for :has() with multiple relative selectors
• Fix csslint slowdowns due to broken strings produced by a bugged @preprocessor