encryption key should be hashed instead of making a repetition

[agudpp]

encrypt / decrypt methods should use a hash function (key -> hash of AES_KEYLEN length)

bool
CryptoHandler::encrypt(const std::string& key, const std::string& data, std::string& result)
{
  // TODO(agudpp):
  std::string the_key = key.size() < AES_KEYLEN
      ? toolbox::StringUtils::duplicateTillNth(key, AES_KEYLEN)
      : key;
  CryptoHandler::Data crypto_data(the_key);
  CryptoHandler crypto_handler(crypto_data);
  return crypto_handler.encrypt(data, result);
}