Allow opt-out for affiliate links

[rugk]

You should make a difference between tracking link part and affiliate links. Although affiliate links of course are also a kind of tracking, they usually just track "where the user came from", in order to compensate the search engine or different things. Now users may like to use this referrers, e.g. as there are also good companies which use that feature or they want to support someone else with that feature.

In order to allow this, please add an option to not strip affiliate links.