python-chess v0.4.0

New in this release:

• Introduce can_claim_draw(), can_claim_fifty_moves() and
  can_claim_threefold_repitition().
• Since the first of July 2014 a game is also over (even without claim by one
  of the players) if there were 75 moves without a pawn move or capture or
  a fivefold repitition. Let is_game_over() respect that. Introduce
  is_seventyfive_moves() and is_fivefold_repitition(). Other means of
  ending a game take precedence.
• Threefold repitition checking requires efficient hashing of positions
  to build the table. So performance improvements were needed there. The
  default polyglot compatible zobrist hashes are now built incrementally.
• Fix low level rotation operations l90(), l45() and r45(). There was
  no problem in core because correct versions of the functions were inlined.
• Fix equality and inequality operators for Bitboard, Move and Piece.
  Also make them robust against comparisons with incompatible types.
• Provide equality and inequality operators for SquareSet and
  polyglot.Entry.
• Fix return values of incremental arithmetical operations for SquareSet.
• Make polyglot.Entry a collections.namedtuple.
• Determine and improve test coverage.
• Minor coding style fixes.