Tiny (230 char) Polyfill for window.doNotTrack
. Checks for:
window.doNotTrack == 1
navigator.doNotTrack == 'yes'
navigator.doNotTrack == 1
navigator.msDoNotTrack == 1'
window.external.msTrackingProtectionEnabled()
And sets value to either 1
(do not track) or 0
(track)