stop providing encode_hash() to encourage using stringify() instead [Compara code has been patched already]

big renaming of hive->worker, analysis_job->job, analysis_job_file->job_file, analysis_job_id->job_id, worker.beekeeper->worker.meadow_type, etc

renamed fetch_from_analysis_id_branch_code method into fetch_all_by_from_analysis_id_and_branch_code

one PREPARE statement per dataflow-to-table call (so works for array of output_ids with identical structure)

testing the idea of analyses that can be empty for blocking purposes (it does not block while it is empty)

fixed a long-standing bug: input_id was supposed to be able to set things (according to compara code)