This update takes advantage of upgrades to the stackEddy function
in neonUtilities 2.1.1, which allows the calibration routines to run
more efficiently on NEON's HDF5 files. For example, calibrate_carbon(),
runs ~2x faster if neonUtilities 2.1.1 is used instead of earlier versions.
Adds the calibrate_carbon() function, which can be used to generate
monthly output files or can be used to bundle all of the months of data
available for an individual site into a single file. In the long-term,
calibrate_carbon() will be the 'workhorse' function for NEON's carbon data,
and calibrate_carbon_bymonth will be deprecated in a future release.