message: Replace CBlockHeader::GetHash with call to SerializeHash
  Removes variability between LE and BE.
  As suggested by
  adapted from bitcoin@a0ae79d77552d9ee67469c934458a3f3bd170858
diff: uint256 CBlockHeader::GetHash() const
  {
  -#if defined(WORDS_BIGENDIAN)
  if (nVersion < 4) {
  +#if defined(WORDS_BIGENDIAN)
  uint8_t data[80];
  WriteLE32(&data[0], nVersion);
  memcpy(&data[4], hashPrevBlock.begin(), hashPrevBlock.size());
  @@ -25,37 +25,13 @@ uint256 CBlockHeader::GetHash() const
  WriteLE32(&data[72], nBits);
  WriteLE32(&data[76], nNonce);
  return HashQuark(data, data + 80);
  - } else if (nVersion < 7) {
  - uint8_t data[112];
  - WriteLE32(&data[0], nVersion);
  - memcpy(&data[4], hashPrevBlock.begin(), hashPrevBlock.size());
  - memcpy(&data[36], hashMerkleRoot.begin(), hashMerkleRoot.size());
  - WriteLE32(&data[68], nTime);
  - WriteLE32(&data[72], nBits);
  - WriteLE32(&data[76], nNonce);
  - memcpy(&data[80], hashMerkleRoot.begin(), hashMerkleRoot.size());
  - return Hash(data, data + 80);
  - } else {
  - uint8_t data[80];
  - WriteLE32(&data[0], nVersion);
  - memcpy(&data[4], hashPrevBlock.begin(), hashPrevBlock.size());
  - memcpy(&data[36], hashMerkleRoot.begin(), hashMerkleRoot.size());
  - WriteLE32(&data[68], nTime);
  - WriteLE32(&data[72], nBits);
  - WriteLE32(&data[76], nNonce);
  - return Hash(data, data + 80);
  - }
  -
  #else // Can take shortcut for little endian
  - if (nVersion < 4)
  return HashQuark(BEGIN(nVersion), END(nNonce));
  -
  - if (nVersion < 7)
  - return Hash(BEGIN(nVersion), END(nAccumulatorCheckpoint));
  -
  - return Hash(BEGIN(nVersion), END(nNonce));
  #endif
  }
  + // version >= 4
  + return SerializeHash(*this);
  +}
  std::string CBlock::ToString() const
  {
  