GD removed (#133) - updated style documentation

en/mapfile/style.txt

@@ -65,11 +65,6 @@ ANGLE [double|attribute|AUTO]
     - The `AUTO` keyword was added in version 5.4, and currently only
       applies when coupled with the `GEOMTRANSFORM` keyword.
 
-    .. note::
-
-      Rotation using `ANGLE` is not supported for :ref:`SYMBOL`\s
-      of `TYPE` `ellipse` with the GD renderer (gif).
-
 ANGLEITEM [string]
     ANGLE[attribute] must now be used instead.
 
@@ -83,6 +78,10 @@ ANTIALIAS [true|false]
     rendering.  Default is false.  Has no effect for the other
     renderers (where anti-aliasing can not be turned off).
 
+    .. warning::
+
+       GD support was removed in Mapserver 7.0.
+
 .. index::
    pair: STYLE; BACKGROUNDCOLOR