made testPythia8_cfg.py run again on e.g. CMSSW_6_2_1
(but a similar problem appears on 5_3_2_patch4):

 - made LHEProducer an EDFilter instead of an EDProducer in the python
   configuration

 - changed Configuration.StandardSequences.VtxSmearedGauss_cff
   to IOMC.EventVertexGenerators.VtxSmearedGauss_cfi
Merge pull request #805 from andreh7/ah-2013-09-12b-lhe-test-fix

Generators fixes -- Fix for GeneratorInterface/LHEInterface/test/testPythia8_cfg.py