[o] scheduled jobs : do not use delayed jobs
[x] put_back in the operate loop ?
[x] test with beanstalk -b ruote_work/beanstalk/ or something
    no need for beanstalk binlog
[o] drop the msgs idiosyncrasies ?
    at first try to go all the way with msgs vs commands
    |
    one of the disadvantages of msgs + commands is that
    schedules are not stored at the same place as the exps/workitems/...
[o] fork beanstalk S(d, 'iface:port', :fork => true)
[o] operate : sign messages (tube AND timestamp)
[o] security issue in #serve (send)
[o] receiver : launchitem ?
[o] 'commands' channel : better name ?

[ ] operate : better name ?

[ ] rw : document participant / receiver (use bs as an example)