Fix bug in MCParticle.xml
fix bug in MCParticle.xml : weird "quasi copy-constructor" does not copy m_flags field. as am immediate result "fromSignal" information is lost for all MC tapes Indeed there areno "signal" particles on our MC! Well, the particles in on tap but they are not marked as signal particles.
Btw - *WHY* we need this strange "quasi-copy" ?
Could it be replaced with normal Copy Constructor (as done for all other classes, e.g. for LHCb::Particle)
(of course LHCb::MCParticle::clone and LHCb::MCParticle::cloneWithKey
in this case need to be fixed also, but I think it is more correct, instead of
using weird "quasi-copy constructor".)