Precompute size and action count for bulk indexing
Precompute size and action count for bulk indexing

This change to the bulking indexer will prevent the max request size and the
bulk request size from being exceed. When a bulk indexing action is requested,
the bytesize of that action is computed first. If adding this action to the
queue would cause the `request_size` to be exceeded, then the bulk request is
immediately dispatched and the new action is added as the first action for the
next bulk request.

github/elastomer-client,github/elastomer-client