Make it 15 days long because we want to use it in place of
`Overlap/Tests/Input/Region_2_SHPC`.

Because variables in `grid_nml` should be all defined in the input file.

We are reverting commits 35fad1b7 and df2b397d because we want the
program `eddy_graph.sh` to read an SHPC containing a single
orientation.

Instead of hard-coding a value.

Instead of reading `extr_map.nc`, `ishape_last.txt` and shapefile
extremum. The problem was the consistency between `extr_map.nc` and
the two other files. `extr_map.nc` contains eddies with the two
orientations while extremum now contains a single orientation, with
eddies renumbered.

Since it is now possible to have one or more SHPC as arguments.

`NSODS_in.txt` and `non_successive_overlap_in.txt` were the only files
left in directory `Region_4`. Not enough files to justify a directory.

Instead of asking the user to define it. So ne no longer need the file
`read_snapshot_nml.txt` for programs `test_read_snapshot` and
`test_send_recv`: we can just supply the remaining data in the `input`
key of tests `Read_snapshot` and `Send_recv`.

This file is a left-over from commit b456b50e. It should have been
moved to Tests/Eddies_region_4 in commit 5e0e0deb and deleted in commit
8ed324ff.

This SHPC was made with an old version of `inst_eddies`: it contains
cyclones and anticyclones output together. We use
`$tests_old_dir/Inst_eddies_loop` instead. See also commit 8ed324ff.

Move the test `Inst_eddies_lopp` earlier in the test series because we
are going to use its results in subsequent tests.

Because we are going to use it in `test_nearby_extr`.

This is necessary since we now output separately cyclones and
anticyclones from `inst_eddies.`

This is more comfortable. Furthermore, it is going to be necessary
when we extend the script to several input SHPC.

For an animation, we want several dates so we need `ishape_last.txt`.

`make_animation` seems too general, the reader may think it is an
object of Matplotlib.

Write `SHPC*` instead of `SHP_triplet_*` directories.

Required since commit f9f99c4.

Since commit 8842ed2, the tests use
`$tests_old_dir/Extraction_eddies_region_4`, which contains two
SHPC. Just use one of them.

Rename `Region_1_SHP_triplet_noise` to `Region_1_SHPC_noise`.

Bug was introduced in commit 8c91ffe5.

Run it with two dates and the new input NetCDF files. Two dates so it
can replace the SHPC that was in `$src_dir/Tests/Eddies_region_4`.

Instead of `$src_dir/Tests/Eddies_region_4`. Because
`$src_dir/Tests/Eddies_region_4` was made with an old version of
`inst_eddies`: cyclones and anticyclones output together.

Since it is a test on script which is in Analysis.

To regroup statements which depend on the shapefiles.