Allow user to specify list of jobs that should not be considered as running by JobIsRunning condition

There are some jobs running in Eclipse workspace we are testing that we don't care about most of the time. E.g. jobs for recreating developer's help cache files - it does not block jobs like building workspace or project, running projects etc. but it's still not a system job ad it's running. I want to be able to filter such jobs out of the list of running jobs when I need to. I considered creating special condition for this, it's probably viable solution too...