minor fix to nmap2 time library routine

This bug is so esoteric that I won't bother sending it out to the gembud list. 
I was unable to plot surface data in nmap2 from last February using the pop up 
"set time" widget. After putting in a bunch of write statements, I traced the 
symptom to $GEMPAKHOME/source/nmaplib/nsf/nsfdspl.f where it was calling
nsf_tlst and using endtim. Since my time window was far from the endtim, it was 
not plotting any data. I switched endtim to dattim and things appear to be 
working both on current data and retrospective data.

Here's the line in nsfdspl.f that was modified. 


c jdh 01/01 replaced endtim with dattim in call as it made it impossible
c to plot data from previous year
        CALL NSF_TLST ( alias, cycle, isbcat, dattim, mrange,
     +                  timstr, lenstr, numt, iret )

I'm not sure if this solves the problem entirely, but at least I'm looking at 
both current and old surface data now.

Regards,

John