add hexagon symbol to basic symbols

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@70136 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/symbol/symbol/basic/hexagon

@@ -0,0 +1,14 @@
+VERSION 1.0
+BOX -1 -0.8660254037844386 1 0.8660254037844386
+POLYGON
+    RING
+        LINE
+            0.5 0.8660254037844386
+            1 0
+            0.5 -0.8660254037844386
+            -0.5 -0.8660254037844386
+            -1 0
+            -0.5 0.8660254037844386
+        END
+    END
+END