Write the number of met files used to CONTROL file

Required by the HYSPLIT parser. Uses the length of
the met files list to dynamically generate the
value. Appends to existing CONTROL file.
Write met file paths to CONTROL file

Uses a loop to extract values from the met files
vector object. Alternates between the met file
path and the met file (with newlines in between).
Appends to existing CONTROL file while looping.
Write path for trajectory output files to CONTROL
Write name of output filename to CONTROL

Uses the filename construction defined earlier.
Add comment about CONTROL file writing being complete
Close the inner (hour) loop
Execute the model run

Provides a directive for the UNIX system to create
a subshell, move to the working directory (where
CONTROL now resides), and to execute the HYSPLIT
standard trajectory binary. The ‘&&’ operator
allows for error catching.