Fixed a problem where members of a deleted mailing list were hanging around.

This would cause duplicate members (e.g. owners) if you created, deleted and
then recreated the mailing list.

Mailman.app.create -> Mailman.app.lifecycle; Mailman/doc/create.txt ->
Mailman/doc/lifecycle.txt; also added a remove_list() function.

Added SubscriptionError base class, made HostileSubscriptionError inherit from
that, and added a new AlreadySubscribedError.

Rewrote bin/rmlist to use the new lifecycle.remove_list() function.

IAddress.subscribe() must now throw an AlreadySubscribedError if the address
is already subscribed to the mailing list with the given role.

Added a Subscribers roster, attached to the IMailingList which gives access to
all subscribers of a mailing list, regardless of their role.  Added a new test
for this roster.

2 files changed, 11 insertions, 2 deletions

diff --git a/Mailman/interfaces/address.py b/Mailman/interfaces/address.py
index 6b00d7915..1e654a2fc 100644
--- a/Mailman/interfaces/address.py
+++ b/Mailman/interfaces/address.py
@@ -56,10 +56,14 @@ class IAddress(Interface):
         None if the email address has not yet been validated.  The specific
         method of validation is not defined here.""")
 
-    def subscribe(mlist, role):
+    def subscribe(mailing_list, role):
         """Subscribe the address to the given mailing list with the given role.
 
-        role is a Mailman.constants.MemberRole enum.
+        :param mailing_list: The IMailingList being subscribed to.
+        :param role: A MemberRole enum value.
+        :return: The IMember representing this subscription.
+        :raises AlreadySubscribedError: If the address is already subscribed
+            to the mailing list with the given role.
         """
 
     preferences = Attribute(
diff --git a/Mailman/interfaces/mlistrosters.py b/Mailman/interfaces/mlistrosters.py
index 9cd20e3ef..86cd4ec91 100644
--- a/Mailman/interfaces/mlistrosters.py
+++ b/Mailman/interfaces/mlistrosters.py
@@ -61,3 +61,8 @@ class IMailingListRosters(Interface):
         postings to this mailing list, regardless of whether they have their
         deliver disabled or not, or of the type of digest they are to
         receive.""")
+
+    subscribers = Attribute(
+        """An iterator over all IMembers subscribed to this list, with any
+        role.
+        """)