represent option of combobox
Content of tag used as option label
Attributes
value - value of option
css - styles of option
img_src - image for combo with images
value for related option
if skipped - value will be set the same as option's label
can contain any HTML, while it correctly escaped
any css text, which need to be applied to option in question
for combo with images , this attribute contains url to image related to option ( if none set, default image will be used )
has no sense for combo in default mode ( without images )
just top xml tag, has no special meaning
Optional attributes
add - set mode of options adding
If attribute exists - options from XML will be added to existing list,
in other case, all previous options will be deleted