v4.0.4

• Make Stylebot usable in Arc (#1212)
• Vivaldi: no longer open the side panel after installing or updating, and hide the Side panel option (#1215)
• Keep the options page's style editor open after saving, save it with Ctrl+S / ⌘S, and only enable Save when there are changes (#1207, #1209)
• Stop syncing every time the popup opens; Stylebot still syncs in the background, and Sync now syncs on demand (#1213)
• Fix "A listener indicated an asynchronous response…" errors showing up in page consoles (#1214)