JPSSnagg

nagg_write_granules.c:
	Added code to fail instead of seg fault when no granules 
	of requested product are found.
nagg_options.c:
	Add compatible_products() function, and always call it, even when 
	-g no is in the command options.  compatible_products() currently 
	checks if all products use the same geoproduct.  In the future, 
	extended compatibility for the geoproducts with terrain corrected 
	versions will be added to the function.
	Added code to allow -t <products> and -g <geoproduct> options in 
	the same nagg command.
nagg_get_granules.c:
	Added 6 functions called directly or indirectly freom nagg_get_granules() 
	to break the 500+ line function into more manageable and more easily 
	understood pieces.  This corrected the incorrect listing of their own 
	filenames as geofiles for geolocation granules.

Tested on jam and koala, with gcc and icc compilers.