[MITgcm-support] diagnostics pkg

[Dimitris Menemenlis]

Martin, I regularly use the following and it does not seem to cause any problem:

   frequency(11) = 21600.,
    fields(1,11) = 'THETA   ',
    levels(1,11) = 1.,
    filename(11) = 'SST',
   frequency(31) = 2635200.,
    fields(1,31) = 'THETA   ',
    filename(31) = 'THETA',
    fileflags(31)= 'D       ',