JPSSnagg

Fixed compose_output_fname() so that it is producing correct output file name, geo file name,
and creation Date strings.
Completed main() to call "start_write, write, end_write" in the correct loop.
The structure is completed to support 1 product (i.e. -t XXX is one product only).
Assume granule table has perfect sets of (n-products + 1) granules.
Currently, only "-n 1" works since write_granules failed to write more than
1 set of granules.

Tested: koala and jam.