PFParticle duplicate bug fix

A bug in the PFParticle collection was introduced in cms538v0. Due to the way PFCandidateCollections are implemented in CMSSW, the ntuplizer was being unable to associate two identical PF particles correctly, causing the stored collection to hold duplicated objects in some cases. The bug is fixed in src/SusyNtuplizer.cc. Validation was run using the relval tool and the fix was confirmed to be doing exactly only what its supposed to.
macro/SusyEventAnalyzer.cc has an example workaround of the bug for the time being. This part shall be removed once the repository is ready for the production of the next round.