discover already running builds in presence of queue

we don't start new builds when there's a queue
because jenkins doesn't want to tell us anything
about its queue via rest

however, we should try to discover already running jobs even
when there's a queue
recognize known running by jenkins url
avoid double-commenting -- TODO: but why?
minor tweak for force rebuild

this will be simplified when we switch to building only one job
not bothering to improve it further