and test_set_all_outerm.

values at longitude boundaries, in case of periodicity.

Add argument "periodic" to procedures get_snapshot and
set_all_outerm. Duplicate values at longitude boundaries in ssh, u, v
if periodic. set_all_outerm can now call local_extrema with periodic
true. In procedure set_all_outerm, we shift the longitudes of outside
points if necessary.

In program test_get_snapshot, define periodic from step and nlon.

For ssh, missing value is huge(0.). We have to take a large value
because Contour_531 has an argument zmax for missing values. For
velocity, missing value is a quiet NaN. We have to take this because
we need to know if the interpolation procedure in mean_speed has not
used any missing value and we do not want to alter the interpolation
procedure itself.

In local_extrema, we accept as local extrema only points with 8 valid
values around them.

When we look for the maximum speed contour, we are hoping that good
contours do not englobe missing values. If this happens, the program
aborts.

When computing the mean speed on a contour, we are hoping that the
interpolation of speed on contour points does not use missing
values. If this happens, the program aborts.

Draw coastlines in plot_snaphot.py. At the same time, this allows the
use of any projection.

out-of-range index so add min when calculating urc.

Bug fix in procedure good_contour. polygon_contains_point should not
be called if polyline is not closed.

Procedure polygon_contains_point became unpure so remove pure for
procedure inside_4 too.

In program test_good_contour, read corner and step from namelist
rather than from coordinates in NetCDF file. Makes it possible to use
the same NetCDF file with different coordinates. Also read
outside_points from a file rather than standard input so there is no
need to specify in advance the number of outside points.

Take into account the possibility that no outermost contour was found
in program test_set_outermost_contour. Also, use fixed names for input
files because it is not convenient to require a particular order of
these two files on the command line.

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.