o Cupcake fills in homePath.maxDataSizeMB and coldPath.maxDataSizeMB with
  zero instead of null, so the calculations that depend upon this value being
  null need a helping hand to work properly.
o Keep track of these macros.
o Use this macro to null out the homePath.maxDataSizeMB and
  coldPath.maxDataSizeMB fields to put them back the way we Fire
  Brigade expects them.
o Treat a zero in homePath.maxDataSizeMB or coldPath.maxDataSizeMB as
  null to prep the data for what Fire Brigade expects.
o It seems that this is part of what we need to get the "old style"
  display of the events table back.
o Combine the two graphs into one to show the limit and the per-index
  trend as one plot (though in nascent environments the scale of this
  might get weird).