[flexcoders] Reflect column sorting in AdvancedDataGrid

[Dennis van Nooij]

I'm using an AdvancedDatagrid where my sorting is done on the server
(total result set is bigger than the list shown at client). So when I
click a header, sort info is added to the request and result comes
back sorted correctly. My question is: How can I provide feedback on
how the results are sorted? Arrows on the columns are gone, probably
because dataprovider was refreshed. Is there a way to manually enable
those arrows again ?