Bug 127289 [Markers] SystemFilter and group selection state not preserved
We are not preserving the selection state of the system filters or which group is selected.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerView.java
boolean buildDone = true;
		private Collection pendingMarkerUpdates = Collections
				.synchronizedSet(new HashSet());
		boolean refreshAll = false;
		private Collection categoriesToExpand = new HashSet();
		UpdateJob() {
			super(MarkerMessages.MarkerView_queueing_updates);
		}
		/**
		 * Refresh the changed list.
		 * 
		 * @param changed
		 */
		void refresh(Collection changed) {
			if (refreshAll) {
				return;
			}
			pendingMarkerUpdates.addAll(changed);
		}
		/**
		 * Refresh the whole view
		 */
		void refreshAll() {
			refreshAll = true;
			pendingMarkerUpdates.clear();