NoScript v2.0.9+ does the same thing Rated 5 out of 5 stars
The two HTTP headers, X-Behavioral-Ad-Opt-Out and X-Do-Not-Track, are by default now added to each HTTP request by NoScript since v2.0.9. This feature is customisable in NoScript, i.e., switching the feature off/on by toggling the boolean setting noscript.doNotTrack in about:config.
Consquently 'Universal Behavioral Advertising Opt-out' is pretty much redundant. Anyone who uses Firefox is far more likely to install NoScript than 'Universal Behavioral Advertising Opt-out'.
Anyway thanks to the Christopher Soghoian and Sid Stamm for making known of these two HTTP header opt-outs, which probably will go unnoticed by the vast majority of NoScript users.