Number of attachments :
Right now most objects inside our hierarchy share the Working Directory
configuration parameter which allows us to set the the directory where each
element works. Now this is a nice feature but it may lead to a duplication
of directories and to some confusion about where exactly we are working.
As an instance, we should have actions that work where instructed by the
EventConsumer which usually creates a new dir inside its workdir every time
it receives something; this is done in order to prevent problems of having
different threads working on the same dir with clashing filenames.