commit

If the native platform does not support SWT.ICON_CANCEL a label is
generated for it.
If not active this label is excluded from layout. This leads to similar
behavior as the preference filter box.

Change-Id: I17578dfbda9c6d0c9dfb46fe144cd1ab04f5b88a
Signed-off-by: David Weiser <david.weiser@vogella.com>