Use a universally supported library for file picking

Assets/Plugins/SimpleFileBrowser/Scripts/NonDrawingGraphic.cs

@@ -0,0 +1,19 @@
+using UnityEngine;
+using UnityEngine.UI;
+
+namespace SimpleFileBrowser
+{
+	// Credit: http://answers.unity.com/answers/1157876/view.html
+	[RequireComponent( typeof( CanvasRenderer ) )]
+	public class NonDrawingGraphic : Graphic
+	{
+		public override void SetMaterialDirty() { return; }
+		public override void SetVerticesDirty() { return; }
+
+		protected override void OnPopulateMesh( VertexHelper vh )
+		{
+			vh.Clear();
+			return;
+		}
+	}
+}