memory: add Parameter "Chat history limit"

src/memory/sqlite.py

@@ -265,10 +265,15 @@ class SqliteStorage(object):
         return d
 
     def getHistory(self, from_jid, to_jid, limit=None, between=True, profile=None):
-        """Store a new message in history
-        @param from_jid: source JID (full, or bare for catchall
-        @param to_jid: dest JID (full, or bare for catchall
-        @param size: maximum number of messages to get, or None for unlimited
+        """Retrieve messages in history
+        @param from_jid (JID): source JID (full, or bare for catchall)
+        @param to_jid (JID): dest JID (full, or bare for catchall)
+        @param limit (int): maximum number of messages to get:
+            - 0 for no message (returns the empty list)
+            - None for unlimited
+        @param between (bool): confound source and dest (ignore the direction)
+        @param profile (str): %(doc_profile)s
+        @return: list of tuple as in http://wiki.goffi.org/wiki/Bridge_API#getHistory
         """
         assert(profile)
         if limit == 0: