Displays the "save file" dialog and returns the selected path name.

	// Opens a file selection dialog for a PNG file and saves a selected texture to the file.
	import System.IO;
	class EditorUtilitySaveFilePanel {
		@MenuItem("Examples/Save Texture to file")
		static function Apply () {
			var texture : Texture2D = Selection.activeObject as Texture2D;
			if (texture == null) {
				EditorUtility.DisplayDialog(
					"Select Texture",
					"You Must Select a Texture first!",
					"Ok");
				return;
			}
			var path = EditorUtility.SaveFilePanel(
					"Save texture as PNG",
					"",
					texture.name + ".png",
					"png");
			if(path.Length != 0) {
				// Convert the texture to a format compatible with EncodeToPNG
				if(texture.format != TextureFormat.ARGB32 && texture.format != TextureFormat.RGB24){
					var newTexture = Texture2D(texture.width, texture.height);
					newTexture.SetPixels(texture.GetPixels(0),0);
					texture = newTexture;
				}
				var pngData = texture.EncodeToPNG();
				if (pngData != null)
					File.WriteAllBytes(path, pngData);
			}
		}
	}