merged back changes from 3.4.15
implemented more voting variables

- votings.votes_good (no of upvotes) for all messages
- votings.votes_bad (no of downvotes) for all messages
- votings.total_voted_messages (no of messages which have been voted in
  this thread) for first message in thread
- votings.total_votings_bad (sum of downvotes) for first messages in
  thread
- votings.total_votings_good (sum of upvotes) for first message in
  thread
- votings.total_votings (sum of total votings, total_votings_bad +
  total_votings_good) for first message in thread