Added the same changes to the interface as for 6_2_X, uses newer functions from sherpa, some of the changes are needed in order to work with sherpa 2.1.1
Missed to remove obsolete header
Remove tarballs from repository
Merge pull request #4291 from thuer/CMSSW_7_2_X_sherpa_2.1.1

Sherpa 2.1.1 API changes.