JPSSnagg

Bug fixed: was not filtering/selecting the latest version of granules.
Fixed by creating a new granprod_compar which compares granules ID and Product ID
only, but not granules version. Fixed another error by changing granule_compar
to compare Granule ID and Product ID in ascending order but version information values
in descending order. This corrected sorting order and the granprod_compar together
filter/select the latest version of every granule-product pairs.

Tested: koala.