add a concave deltoid N arrow symbol

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@56761 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/symbol/symbol/n_arrows/n_arrow6

@@ -0,0 +1,32 @@
+VERSION 1.0
+BOX -1 -1 1 1
+STRING
+  ARC 0 0 5 360 0 C
+END
+POLYGON
+  RING
+    LINE
+      0 5
+      4.3301 -2.5
+      0 -1
+      -4.3301 -2.5
+      0 5
+    END
+  END
+END
+POLYGON
+  RING
+    LINE
+        1.15 -4.25
+        1.15 -1.75
+        0.75 -1.75
+        0.75 -3.625
+        -0.75 -1.75
+        -1.15 -1.75
+        -1.15 -4.25
+        -0.75 -4.25
+        -0.75 -2.375
+        0.75 -4.25
+    END
+  END
+END