Fixes some compatibility issues with other addons:
* Tree Style Tab: https://github.com/cowlicks/privacypossum/issues/71
* A Screen Resolution Spoof userscript:
https://github.com/cowlicks/privacypossum/issues/69

Also some small refactoring and doc updates:
* https://github.com/cowlicks/privacypossum/pull/75
* https://github.com/cowlicks/privacypossum/pull/73