Support for
* Themes (new icon set, accessible from add-on settings)
* IP addresses (no longer broken into parts)
* Container tabs (if opening URIs in new tab, respect container, if one exists)

Fixes
* Respect trailing slashes in URIs
* Disable browser action on about:* URIs

New permission requirements:
* cookies: Required to support container tabs (https://wiki.mozilla.org/Security/Contextual_Identity_Project/Containers)

Support subdomains (TLD detection based on https://publicsuffix.org/).

Features:

• Add page action. Enabled by default, but can be disabled from settings ("Hide page action (icon in address bar)".
• Middle click opens link in new tab.

Under the hood:
Fall back to storage.local if storage.sync is disabled.