Add Invert and Status options to PdgCodeFilter
It is sometimes useful to output the truth record of a single
(non-stable) particle species, for example when considering an
exotic heavy resonance. Presently the only way to do so is to
output the entire Delphes/allParticles array, which is inefficient.
This patch adds the option InvertPdg to PdgCodeFilter, which causes
the PdgCodes specified to be *added* to the output array, rather
than removed. It also adds the options RequireStatus and Status,
for additional filtering based on the MC record status. If
RequireStatus is true, than only particles matching Status are
added to the output array.
This patch should be backwards compatible with existing usages of
PdgCodeFilter.
