redfam: article_generator can return talkpage

To make pywikibot.pagegenerators.PageWithTalkPageGenerators unneccessary
so we can manipulate talkpage object directly

Related Task: [FS#161](https://fs.golderweb.de/index.php?do=details&task_id=161)

lib/redfam.py

@@ -514,7 +514,8 @@ class RedFamWorker( RedFam ):
     def article_generator(self,  # noqa
                           filter_existing=None, filter_redirects=None,
                           exclude_article_status=[],
-                          onlyinclude_article_status=[] ):
+                          onlyinclude_article_status=[],
+                          talkpages=None ):
         """
         Yields pywikibot pageobjects for articles belonging to this redfams
         in a generator
@@ -528,6 +529,8 @@ class RedFamWorker( RedFam ):
                                  set to False to get only redirectpages,
                                  unset/None results in not filtering
         @type  filter_redirects  bool/None
+        @param  talkpages  Set to True to get Talkpages instead of article page
+        @type  talkpages  bool/None
 
         """
 
@@ -591,6 +594,10 @@ class RedFamWorker( RedFam ):
             except Break:
                 break
 
+            # Toggle talkpage
+            if talkpages:
+                page = page.toggleTalkPage()
+
             # Yield filtered pages
             yield page