Do not modify dummy argument x of `plot_distr_funct`.

We now want the default behaviour to be renumber. `SHPC_class` expects
sequential eddy indices from 1.

The corresponding modules are not used in the functions.

Invert order of dummy arguments orientation and layer of method
`get_reader`. Take the same order than in the path. `orientation` was at
the end because, at first, in commit d858fb72, it was an optional
argument.

Create function `plot_grid_points` from code which was in the "script
portion" of the module. This new function could be useful when
importing the module for interactive work. Also, creating this
function clarifies the module.

This is the same as the number of extrema, since commit f7c5ec74.

Remove option `--dashed` of script `plot_eddy_contours.py`. This
option was added in commit 5e0e0deb. The dummy argument dashed of
function snapshot is useful because we can call snapshot several times
on the same axes from elsewhere, but I do not see how the option
`--dashed` of script `plot_eddy_contours.py` is useful, since we
create a new figure when we run the script.

Create a new figure in function `plot_distr_funct` if ax is None.

Remove component radius4 of derived type eddy and field radius4 of
`outermost_contour.dbf`. They are not used any longer.

Because there is no time dimension in
`Inst_eddies/Tests/Input/uv_outermost.nc`, for example.

Write files `grid_nml.txt`, `used_config_nml.txt` and `n_slices.txt`.

This will be useful to create `n_dates_1` and `n_dates_14`. It should
be faster for this purpose than using the more general script `filter.py`.

Not used since commit cd8df9d2.

Use method `ishape_range` in function `select_ishapes`.