Resource should be retried based on error code returned from previous request

Heat deals with external services to provision resources and requests to
these services are prone to failure due to hardware/software failures or
network outages.

Heat needs a better retrying logic to minimize user intervention, like
again updating the stack that failed due to temporary failure or
unavailability of service, which could be handled by Heat easily.

When a resource operation fails, it is retried after some time. The
return code/HTTP status code of the resource operation from the previous
request can be used to determine whether to retry again. For example, if
HTTP status code 403 (Forbidden) is returned for a nova server request,
then further retries can be stopped and error be returned. Whether to
retry or not will depend on the status code and will differ for
different resources.

By implementing this we can avoid network bandwidth and computational
resources.