Fix #2082 (xml:lang)

This is now already done in sleekxmpp, so I added a “lang” configuration
option. TODO: use the locale of the system.

data/default_config.cfg

@@ -344,6 +344,11 @@ send_os_info = true
 # Set to false if you don't want people to know that information
 send_time = true
 
+# The language you specify using.
+# This *may* be ysed by an automated entity to send you tailored replies
+# If you don't understand, leave en.
+lang = en
+
 # Configure the number of maximum lines and messages (for each tab) that
 # can be kept in memory. If poezio consumes too much memory, lower these
 # values

doc/en/configure.txt

@@ -197,6 +197,10 @@ section of this documentation.
   The 'server' option will be ignored if you specify a JID (Jabber id)
   It should be in the form nickname@server.tld
 
+*lang*:: en
+
+  The lang some automated entities will use when replying to you.
+
 *lazy_resize*:: true
 
   Defines if all tabs are resized at the same time (if set to false)

src/connection.py

@@ -46,7 +46,8 @@ class Connection(sleekxmpp.ClientXMPP):
                 jid = '%s/%s' % (jid, resource)
             password = None
         jid = safeJID(jid)
-        sleekxmpp.ClientXMPP.__init__(self, jid, password)
+        # TODO: use the system language
+        sleekxmpp.ClientXMPP.__init__(self, jid, password, lang=config.get('lang', 'en'))
         self.core = None
         self.auto_reconnect = True if config.get('auto_reconnect', 'false').lower() in ('true', '1') else False
         self.reconnect_max_attempts = 0