_NAME_
getOverlapStructCount

_PROTOTYPE_
int getOverlapStructCount(int day1996, char *structName);

_SHORT-DESCRIPTION_
Get the number of structs in a particular archive overlap file

_DESCRIPTION_
getOverlapStructCount is used to determine the number of data structs of
type structName in a particular days overlap files.
_
It does this merely by looking at the size of the file and dividing by
the size of a sruct of type structName. If the divide does not return an
integral number, getOverlapStructCount will exit with an error message.

_INPUT_
* day1996 is the day-of-1996.
* structName is the full name of the data type of interest.

_OUTPUT_
* The number of data structures in the overlap data file.