Added the mass and area of the closest jet and the momentum of the lepton
transverse to the closest jet to the electron-jet and muon-jet collections.

Also added a histogram filled with the status 3 particles in the mcparticles
collection and added variables to the channel definition that can be used to
select events based on status 3 particle content.
Added variables to the channel struct for selecting events based on status 3
mcparticle content and a prototype for a function that fills a histogram with
the status 3 particles of each event.
Added an option for appending locations to the list of locattions for an entry
in the database.
Allow for lists of locations in a database entry instead of just a single
directory.