vote_up_down 6.x-2.0-rc1

Changes since DRUPAL-6--2-0-BETA2:

• #841080 by lyricnz | fcjversc: Fixed Warning: Call-time pass-by-reference has been deprecated.
• feature #160609 by lyricnz, marvil07: Added Add nofollow.
• feature #811694 by marvil07, Soren Jones, jsalinas and McO Artista: New widget for splitting of votes in positives/negatives

  Provide implementation for two new aggregation functions for voting_api:
  'positives' and 'negatives'.

  Add the new widget showing that new values.

  Thanks a lot to jsalinas y McO Artista for the design review at DrupalCamp
  in Peru

• task #863902 by marvil07: make the Default widget _the default_ widget.
• feature #672566 by nibblebot, David Strauss, jcisio: Compatibility with Pressflow.