remember the order of positional arguments so we rather use fixed
input file names and no arguments.

test_good_contour has more general input.

test_inside tests only inside, no loop on radius.

procedure get_eddy), with corresponding test.

Take into account the fact that derived type polygon became polyline
in library Contour_531.

Use new procedure null_polyline from library Contour_531.

Correct a sneaky bug in mean_speed: the last point in the polygon
array is a duplicate of the first point, do not take the last point
into account when averaging (and interpolating). Discovered this bug
because the mean speed was not exactly the same for equivalent
polygons with circular permutation.

Change philosophy for the tests: read whole NetCDF variables, prepare
different NetCDF files for different geographical regions if needed;
read all data from file or namelist; read names of files on command
line.

Use generic test_program.sh (which is out of this project) instead of
the specific tests_detection_eddies.sh.

test_set_outermost_contour are in degrees.

local_extrema instead of coding sense of rotation with the sign of
extr_map.

In makefile, we want tags to include sources for test_good_contour,
etc. External file list becomes easier.

Moved test_bilinear_interp.f and test_bilinear_interp.py out of the
project. These are rather tests on Numer_Rec_95.

In test_local_extrema, write to CSV file instead of stdout.