Updating core2Dlatlon to run interp & MA.

I simply imported the modifications from core2D.
Improving 2D_latlon tests based on the regular 2D.
maud4latlonnc now uses maud instead of cmaud.

Temporary solution until finish the tests on cmaud.
Assert check, data and weights must have same shape.
Temporary pipe for cwmean_2D_latlon
Minor upgrade.