@austince While working on examples for the docs, I found an optimization issue that I decided was worth fixing now. My changes are listed below -- the first item is what prompted me to address the change now:

• POST _zentity/resolution/{entity_type}/_bulk now retrieves the entity model once before all jobs, instead of once before each job. If the "entity_type" is not given in the URL, then each job will fetch its own entity model, unless the job has the model embedded in its payload.
• Ensure that an "entity_type" in a single bulk action overrides the "entity_type" in the URL.
• Ensure that an embedded "model" is accepted when "entity_type" is undefined.
• Fail the entire bulk request if the "entity_type" in the URL is not found, but allow single bulk actions to fail without failing the whole request if the action's own "entity_type" is not found.
• Fixed a potential NullPointerException in JSON serialization.
• Removed a needless log message.