Bug fix: do not provide standard input for `inst_eddies_Aviso.py`, it
does not read it.

Use out_cont%closed instead.

`Inst_eddies_12` uses the current revision and so does not contain
invalid eddies.

Move test `R4_15_splitted` before the tests that use it.

Instead of `Inst_eddies_10_splitted`.

Because stat is a module from Python standard library.

Only useful for tests.

Allowing the module to be imported and used conveniently from Python.

This avoids copying `cont_list(n_cont)` to `out_cont` if it has
insufficient area.

Add dummy arguments `cont_list` and `n_cont` to `get_1_outerm`.

Because we are going to add another intent out argument.

Remember that we do not write invalid eddies to shapefiles, so there
are no null shapes in `outermost_contour.shp`. So, in order to predict
the size of output, the interesting statistics is the number of points
divided by the number of non-null outermost contours.

Keep the good contours found when looking for the outermost contour,
subject to a maximum of `n_max_cont` contours. The idea is to use them
later when looking for the maximum-speed contour. Inside function
`get_1_outerm`, we temporarily store the good contours in a local
explicit-shape array, `cont_list`.

Add default initialization for component area of derived type
`ssh_contour`, because we are going to keep contours for which we will
not compute area.

Because the numbering changed when we decided not to write invalid eddies.

I do not remember why I chose to write to standard error. First it is
clearer to write only error messages to standard error. Second the
order of messages on standard error coming from the Fortran code and
from the shapelib C library does not seem deterministic, and this is
annoying to compare runs.

Because the numbering changed when we decided not to write invalid eddies.

Because `$tests_old_dir/Extraction_eddies_region_5/SHPC` is opened
with `SHPC_class` in test `Plot_eddy_contours_window`, which will
create `n_slices.txt`, so there will always be this file only in
`$tests_old_dir/Extraction_eddies_region_5/SHPC`.