validity of an eddy depending not only on its amplitude but also its
surface. (Note that, in this version, the component valid is redundant: one
can simply test the component out_cont%n_points.)

hard-coding them.

Remove component twice of type eddy, no longer needed.

Stdin to Input. Two input dir provided for in tests.json: $input_dir
and $large_input_dir.

Rename everywhere variable nearby_extr to outside_points to avoid
confusion with function nearby_extr. Rename file "nearby_extr.csv" to
"outside_points.csv".

In procedure nearby_extr, include in the selection extrema with
different sign, even if they do not have sufficient amplitude.

Bug fix in read_eddy: use the value of read attribute to define
e%interpolated.

be useful for testing successive_overlap.

for upcoming procedure read_snapshot.

Bug fix in procedure rossby_number: e%speed_cont could be null.