Deselects all selected items in the receiver's list.
<p>
Note: To clear the selection in the receiver's text field,
use <code>clearSelection()</code>.
</p>
@exception SWTException <ul>
<li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
<li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
</ul>
Deselects all selected items in the receiver's list. <p> Note: To clear the selection in the receiver's text field, use <code>clearSelection()</code>. </p>
@exception SWTException <ul> <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> </ul>
@see #clearSelection