added information that a style can be used only on a single mesh at m…

…ore places (refs #909)

starling/src/starling/display/Button.as

@@ -311,7 +311,8 @@ package starling.display
             _textField.style = value;
         }
 
-        /** The style that is used to render the Button. */
+        /** The style that is used to render the button.
+         *  Note that a style instance may only be used on one mesh at a time. */
         public function get style():MeshStyle { return _body.style; }
         public function set style(value:MeshStyle):void { _body.style = value; }
 

starling/src/starling/display/Mesh.as

@@ -231,10 +231,10 @@ package starling.display
         /** The style that is used to render the mesh. Styles (which are always subclasses of
          *  <code>MeshStyle</code>) provide a means to completely modify the way a mesh is rendered.
          *  For example, they may add support for color transformations or normal mapping.
-         *
-         *  <p>The setter will simply forward the assignee to <code>setStyle(value)</code>.</p>
+         *  Beware: a style instance may only be used on one mesh at a time.
          *
          *  @default MeshStyle
+         *  @see #setStyle()
          */
         public function get style():MeshStyle { return _style; }
         public function set style(value:MeshStyle):void

starling/src/starling/text/TextField.as

@@ -429,7 +429,8 @@ package starling.text
         public function get pixelSnapping():Boolean { return _meshBatch.pixelSnapping; }
         public function set pixelSnapping(value:Boolean):void { _meshBatch.pixelSnapping = value }
 
-        /** The style that is used to render the text's mesh. */
+        /** The style that is used to render the text's mesh.
+         *  Note that a style instance may only be used on one mesh at a time. */
         public function get style():MeshStyle { return _meshBatch.style; }
         public function set style(value:MeshStyle):void
         {