Docs
update test files for @originate changes
test robustness of job_history when exceptions are thrown. Are preceding jobs always saved to the database?
add @originate;
bug fix: missing job_history support in graph_printout_graph();
bug fix: internals of pipeline_run should treat multithread parallelism in the same way as multiprocess parallelism;
bug fix: get_output() should be more defensive when @split @subdivide jobs do not return a list (but e.g. a file name);
bug fix output parameters do not necessary contain names of successively created file
bug fix: insert 'all_tasks_complete()' into parameter queue to signal end of queue when interrupted by an exception. Otherwise, thread hangs