Listening to Multicast.

[Vance Shipley]

We are still missing the add_membership and drop_membership 
options.  There is a very simple patch required to add these
options into inet.erl.  The options are implemented however 
they are missing from inet:options/0 and so are unreachable.

Raimo had said the patch was accepted for the R9 release
however that doesn't seem to have happed.

	-Vance

http://www.erlang.org/ml-archive/erlang-questions/200303/msg00314.html
http://article.gmane.org/gmane.comp.lang.erlang.patches/15
http://article.gmane.org/gmane.comp.lang.erlang.patches/19