List admins deletion through the command line

[dverdin]

See Issue #524 for discussion.

The aim of this PR is to give administrators the possibility to delete list administrators (owners or editors) through the command line.
As it is based on a Request handler, it also introduces the possibility to do so through the Sympa API (SOAP, and later REST).
It is complemented by two other PR, allowing addition and update of list admins.

Adding :
- a Request handler dedicated to list admin deletion,
- a sympa.pl command line option to delete a list admin, based on this handler,
- tests for the handler module.

The command line allows the following options:

sympa.pl --delete_list_admin [email protected] --list=list@domain|--robot=domain [ --role=role ]

- "--email" is the list admin's email address. It is mandatory.
- "--role" may specify "owner" or "editor". If "--role" is absent, both values are used.
- You must specify either "--list" or "--robot". If you specify "--robot", the user is removed from the role in all this robot's lists.

Please note that this command WILL NOT remove the user if it is the last list owner.

[ikedas]

Obsoleted by PR#1251. Close.