Better Argument Parsing for handlers

[SakiiR]

In Fact a better Argument parsing would be better.

https://docs.python.org/3/library/argparse.html

Il would be great if thoses kind of part use argparse:

def jabber_cmd_jabber(data, buffer, args):
    """ Command '/jabber'. """
    global jabber_servers, jabber_config_option
    if args == "" or args == "list":
        jabber_list_servers_chats("")
    else:
        argv = args.split(" ")
        argv1eol = ""
        pos = args.find(" ")
        if pos > 0:
            argv1eol = args[pos+1:]
        if argv[0] == "list":
            jabber_list_servers_chats(argv[1])
        elif argv[0] == "add":
            if len(argv) >= 4:
                server = jabber_search_server_by_name(argv[1])
                if server:
                    weechat.prnt("", "jabber: server '%s' already exists" % argv[1])
                else:
                    kwargs = {'jid': argv[2], 'password': argv[3]}
                    if len(argv) > 4:
                        conn_server, _, conn_port = argv[4].partition(':')
                        if conn_port and not conn_port.isdigit():
                            weechat.prnt("", "jabber: error, invalid port, digits only")
                            return weechat.WEECHAT_RC_OK
                        if conn_server: kwargs['server'] = conn_server
                        if conn_port: kwargs['port'] = conn_port
                    server = Server(argv[1], **kwargs)
                    jabber_servers.append(server)
                    weechat.prnt("", "jabber: server '%s' created" % argv[1])
            else:
                weechat.prnt("", "jabber: unable to add server, missing arguments")
                weechat.prnt("", "jabber: usage: /jabber add name jid password [server[:port]]")
        elif argv[0] == "alias":
            alias_command = AliasCommand(buffer, argv=argv[1:])
            alias_command.run()
        elif argv[0] == "connect":
# [...]