new symbol: nice instead of arrows for vector size+dir

  (merge from devbr6)

matlab/octace commands to generate/modifty it:
deg2rad = pi/180;

theta = 7.5;
y0 = 0.9;

x0 = y0 * atan(theta * deg2rad)

%%%% coords of half-circle on top
r = x0;

clear xy;
xy(size(0:10:180), 1:2) = NaN;
xy(:) = NaN;

i=0;
for theta=0:10:180
   i=i+1;
   xy(i,1) = r * cos(theta * deg2rad);
   xy(i,2) = r * sin(theta * deg2rad);
end

for i=1:length(xy)
  disp(sprintf('      %.4f  %.4f', xy(i,1), xy(i,2)+y0))
end


git-svn-id: https://svn.osgeo.org/grass/grass/trunk@38839 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/symbol/symbol/extra/ping

@@ -0,0 +1,29 @@
+VERSION 1.0
+BOX -.3 -.3 .3 .3
+POLYGON
+  RING
+    LINE
+      0 0
+      0.1171  0.9000
+      0.1154  0.9203
+      0.1101  0.9401
+      0.1014  0.9586
+      0.0897  0.9753
+      0.0753  0.9897
+      0.0586  1.0014
+      0.0401  1.0101
+      0.0203  1.0154
+      0.0000  1.0171
+      -0.0203  1.0154
+      -0.0401  1.0101
+      -0.0586  1.0014
+      -0.0753  0.9897
+      -0.0897  0.9753
+      -0.1014  0.9586
+      -0.1101  0.9401
+      -0.1154  0.9203
+      -0.1171  0.9000
+      0 0
+    END
+  END
+END