DIVAndNN implementation

Here is a first cut at the DIVAndNN implementation for BlueCloud: 18c3278a

So far, it uses global SDC Temperature and Salinity (rather than WOA) as co-variables. The original temperature and salinity files are guite large, so I put the averages here on dox (folder bluecloud-plankton/data shared with you) so that you do not need to download these 24 files manually.

Can you:

• check at your end if this works on your machine,
• augment the co-variables with other parameters from the WOA: ? Time averages are already provided, you need just to interpolate (you might want to look at DIVAndNN.saveinterp).