[Mailman-Developers] [CLI Project] Preference management commands added

[Rajeev S]

Hi,

As promised, I have completed the preference related commands and pushed 
it as revision 60 [1].

The preferences form a new scope, along with user, domains and lists. 
There are 2 commands associated
with the `preference` scope.

1.Show Preference

   ./mmclient show preference [scope] [scope_args] [key]

That is, to view a preference of a list member

   ./mmclient show preference member --email a at b.com --list 
list at domain.org receive_own_postings


2. Update Preference

Similar to the above command

   ./mmclient show preference [scope] [scope_args] [key] [value]

   ./mmclient show preference member --email a at b.com --list 
list at domain.org receive_own_postings true

The supported preference scopes are

   global [2]
   user --email
   address --email
   member --email --list

Also, the command scope resolution code in cmdparser.py, which was 
repeated once per scope, has been replaced
with a better and faster approach.

Footnotes:

[1] 
http://bazaar.launchpad.net/~rajeevs1992/mailman.client/mailmancli/revision/60

[2] Upon updating/editing the global preferences, a `HTTP Error 405 : 
Method not allowed is raised`. I tried as sudo but still
no good. Is that a mailman bug or a design decision?