without this, it's difficult to implement a graceful restart (stop accepting new connections but continue servicing old ones ... eventually all old connections are finished and you can shutdown).
I've attached a patch that adds such a function.
patch that breaks out the functionality of evhttp_free into 2 functions (one that stops listening and the original evhttp_free) and call the former from the latter.
You can do this in Libevent 2.0 with the evhttp_del_accept_socket function. Libevent 1.4 is in "stable" status: no new features are getting added.