jp (base): add --max option:

when MULTI_ITEMS is set, --max options is automatically added, except if NO_MAX flag is set.

frontends/src/jp/base.py

@@ -353,6 +353,9 @@ class Jp(object):
         elif flags.multi_items:
             # mutiple items
             pubsub_group.add_argument("-i", "--item", type=unicode_decoder, action='append', dest='items', default=[], help=_(u"items to retrieve (DEFAULT: all)"))
+            if not flags.no_max:
+                pubsub_group.add_argument("-m", "--max", type=int, default=10,
+                    help=_(u"maximum number of items to get ({no_limit} to get all items)".format(no_limit=C.NO_LIMIT)))
 
         if flags:
             raise exceptions.InternalError('unknowns flags: {flags}'.format(flags=u', '.join(flags)))