The description was wrong since commit e35226da.

Do not use option `--node` in test of `plot_components.py`, since we
are going to remove it.

Move function `partition_graph_date` from script `report_graph.py` to
script `edgelist_to_Graphviz.py`. `partition_graph_date` is no longer
used in `report_graph.py`.

Because we are going to add a function and we will need to import
`edgelist_to_Graphviz`.

The Graphviz file can be created with `edgelist_to_Graphviz.py`.

`argparse` is overkill here.

Just write a new edgelist. The Graphviz file can be created afterwards
with `edgelist_to_Graphviz.py`.

Move part of tests to new test series in sub-directory.

Rather than from current series of tests.

Move Python scripts to new sub-directory `Analysis`.

Move component extraction functionality to new script
`extract_component_nx.py`. For clarity.

Note that llcrnrlat and urcrnrlat were not used.

So we can use the output file of `extract_component.py` as input of
`draw_segments.py`, for example.

As in script `Trajectories/segments.py`.

These files will usually be created in the same directory.

Rather than from current series of tests.