Modified examples to use DECAY.DEC instead of DECAY_2010.DEC.

Changed EvtExternalGenList to assume Pythia8 codes are
used in decay files by default, which is the case for DECAY.DEC.
Updated the setupEvtGen.sh script to work with Pythia 8.2x versions.
Slightly increase max prob for two-body VVP modes
(from LHCb code merge changes).