Unsubscribe from one specific list

[franck-grenier]

Unsubscribe php view removes all subscriptions of a user. It could be useful to be able to remove only one subscription in one specific list.

A parameter "[list_id]" could be added to URI "/ownewsletter/unsubscribe/[userhash]/" and passed to OWNewsletterUser::unsubscribeFrom to do the job.