Added hg_summary_cb, which writes statistical outputs using climatology_bounds

h1_summary_cb - computes means and standard deviations of hourly output
netCDF files, creating two new netCDF files (one for the means and one
for the standard deviations) for each month by hour of day, just like
h1_summary and h1_summary2. However, this version does not create a
new "hour" dimension on every output field. Instead, it follows the
CF-1.0 standard that requires a "climatology_bounds" variable (instead
of the normal "time_bounds" variable) and each hour-of-day mean/standard
deviation is stored as a time slice.

h1_summary_cb will be used for the remaining C-LAMP experiments, starting
with Experiment 2.2.

Changed h1_summary/h1_summary2 to write a timestamp that is centered on the time bounds.

h1_summary and h1_summary2 previously wrote out a timestamp representing the
last time entry in the last file to be summarized. Now, to follow convention,
the timestamp is recomputed as the mean of the first and last time_bounds,
where the first time_bounds value is the first value from the first time
entry in the first file and the last time_bounds is the second value from
the last time entry in the last file.

Changed setup_robin1.bash and Makefile for use on robin1 machine.

Fixed h1_summary and h1_summary2 to correctly construct time_bounds values.

h1_summary and h1_summary2 previously used the time_bounds from the last time
value from the last input file when summarizing, suggesting that the field
values were appropriate only over that short time range instead of the complete
time period over which the statistics were calculated. C-LAMP Experiment 1
runs used the previous code, so the time_bounds were incorrect in the
statistical summaries produced. C-LAMP Experiment 2 runs will use this new
code for production of statistical summaries.

Initial commit of post-processing codes for C-LAMP experiments

add_total_fields - modifies model output netCDF files to add fields computed
from fields within the files.

h1_summary - computes means and standard deviations of hourly output netCDF
files, creating two new netCDF files (one for the means and one for the
standard deviations) for each month by hour of day.

h1_summary2 - the same as h1_summary, but it uses more memory to read in more
timeslices at once, so it may be faster on some machines.