User Download Organization

The user download organization defines how the data is delivered to the
users of the archive. 

A proposed user download structure was suggested the Feb 15 IRTF-IPAC telecom email by TD.

(Proposed) Basic user delivery structure:

   ./$INSTUMENT/$PROGRAM_ID/$DATE/*fits
   ./ielog/ielog_$DATE.zip
   ./weather/weather_$DATE.zip
   ./program_info/

Would allow multiple $DATE, or multiple deliveries to be copied to a top level directory,
and still keep files organized.

An example using 2 $DATE (2017-02-15, 16) and 2 PROGRAM ID (2017A001, 2017A009)

   ./index file, or wget scripts, or ? (TBD based on delivery method).
   ./bigdog/
      |---/2017A001
         |---20170215/*fits
               |---20170216/*fits
               |---/2017A009/
         |---20170216/*fits
   ./guidedog/2017A001
         |---20170215/*fits
         |---20170216/*fits
   ./ielog/ielog_20170215.zip, ielog_20170216.zip
   ./weather/weather_20170215.zip, weather_20170216.zip
   ./program_info/program_2016A001.txt, program_2017A009_txt


This structure is differ from the group delivery structure  used to send the data
to IPAC. The IPAC archived has a 'group of FITS' as a search/display unit that
isn't necessary needed outside of the archive. This may present an issue, as
we don't want to re-package data at IPAC before downloading. This could be
avoided by provide download script to the archive suer, ie:

rcp iarchive:/IRTF