Switch svn2rss.py from pickle to cPickle, and remove needless use of StringIO, bringing a noteworth speed-up (~30% faster when generating many items).
Switch svn2rss.py from pickle to cPickle, and remove needless use of StringIO,
bringing a noteworth speed-up (~30% faster when generating many items).

* contrib/hook-scripts/svn2rss.py: Import cPickle, not pickle.
  Stop importing StringIO.
  (Svn2RSS.pickle): Stop needlessly using a StringIO object.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion