heppy_batch number of jobs wrong?

[cbernet]

component 101 files, split factor 2 -> less than 50 jobs?

[cbernet]

when a root file is missing, even though heppy_check was ok, hadd fails.
improve heppy_check
make sure that if a root file is missing, the chunk is removed, and the user is warned. but the hadd should still complete with the good chunks