Revised Awsresponse.cs implementation to avoid DeadLock while using task<T>.Result based on

AwsResponse

public XElement ExecuteRequest(NameValueCollection arguments)
    {
      var task = ExecuteRequestAsync(arguments);
      return task.Result;
    }

    public async Task<XElement> ExecuteRequestAsync(NameValueCollection arguments)
    {
      arguments = AddStandardArguments(arguments);
      var argumentString = WriteQueryString(arguments);
      var requestUrl = string.Format(
          "{0}://{1}/?{2}",
          simpleDbProtocol,
          simpleDbUrl,
          argumentString);
      var requestMessage = new HttpRequestMessage(HttpMethod.Get, new Uri(requestUrl));

      //Please refer to : http://tech.pro/tutorial/1229/asynchronous-programming-in-c-advanced-topics
      var responseMessage = await _httpClient.SendAsync(requestMessage).ConfigureAwait(false);

      if (responseMessage.IsSuccessStatusCode)
      {
        return ProcessAwsResponse(responseMessage);
      }

      var errors = ProcessAwsResponse(responseMessage);
      //TODO: (CV) Should not be throwing from the async handler. Maybe change the method signature to return a result wrapper which indicates the Status of result???.
      throw new SimpleDbException(string.Format(
          "Error {0} {1}: AWS returned the following:\n{2}",
          (int)responseMessage.StatusCode,
          responseMessage.StatusCode,
          string.Join("\n", errors.Descendants(sdbNs + "Error")
              .Select(error => string.Format("{0}: {1}",
                  error.Element(sdbNs + "Code").Value,
                  error.Element(sdbNs + "Message").Value)))));
    }