TimePerEvent convention

Just to make sure we'll never come up with different definitions, let me write in this wiki what TimePerEvent is meant to be in ReqMgr.

TimePerEvent = (number of events processed) / (walltime of the job)

Thus, if we get a request with:

• Multicore=8 and TimePerEvent=5: it means we'll process 10 events in 50 secs (using 8 cores)
• Multicore=1 and TimePerEvent=5: it means we'll process 10 events in 50 secs (using 1 core)