scrapper -> scraper

Woops!

scrapper: a fighter or aggressive competitor, especially one always
ready or eager for a fight, argument, or contest: the best lightweight
scrapper in boxing; a rugged political scrapper.

That's not what I meant.
Sort unmangled addresses in the configuration file by frequency.

Fixes #287
Rewrite Group.get_topics to be iterative rather than recursive.

Fixes #284
Make whole script comaptible with python 2.6

How low we fell :(

Also:
 * On Python 2.6 we have to send bytes to proc.communicate() not
   unicode str (Fixes #288)
Eliminate do_redirect() method.

One less HTTP connection, which was actually not needed.