Accept total_files in FileBased splitting.

Hi Andreas,  Thank you very much for the explanation. Now I understand mostly. :smile: 

> On the other hand, "totalFiles" tells how many files the user wants to run over after having done any 'goodness quality filtering' over the files.

Is totalFiles for a given workflow?  i.e. are you restricting the number of files for whole workflow?
jobSplitting uses generator to create the job. If that is the case self.limit should be always bigger than totalFiles to this code to work. Is that the precondition? Or am I misunderstood something?

https://github.com/dmwm/WMCore/blob/master/src/python/WMComponent/JobCreator/JobCreatorWorker.py#L137