Add cleanup method to profiles to support logging out.

src/libprs500/ebooks/lrf/web/convert_from.py

@@ -160,6 +160,10 @@ def process_profile(args, options, logger=None):
         finally:
             os.chdir(cwd)
     finally:
+        try:
+            profile.cleanup()
+        except:
+            pass
         if tdir and os.path.isdir(tdir):
             if options.keep_downloaded_files:
                 print 'Downloaded files in ', tdir

src/libprs500/ebooks/lrf/web/profiles/__init__.py

@@ -212,6 +212,9 @@ class DefaultProfile(object):
         return articles
 
     
+    def cleanup(self):
+        pass
+    
     @classmethod
     def process_html_description(cls, tag):
         src = '\n'.join(tag.contents)