Bug 214649 [Markers] Allow markerAttributeGroupings and markerGroups to be specified within contentGenerators
With everything at the top level it is hard to see the relation to a contentGenerator and the groups and attribute groupings. These should be sub elements a la menus.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/CachedMarkerBuilder.java
* Load the group with id from the child if there is a matching system group
	 * registered.
	 * 
	 * @param child
	 * @param id
	 * @return <code>true</code> if a matching group was found
	 */
	private boolean loadGroupWithID(IMemento child, String id) {
		Iterator groups = getAllFilters().iterator();
		while (groups.hasNext()) {
			MarkerFieldFilterGroup group = (MarkerFieldFilterGroup) groups
					.next();
			if (id.equals(group.getID())) {
				group.loadSettings(child);
				return true;
			}
		}
		return false;
	}
	/**
	 * Load the settings from the memento.
	 * 
	 * @param memento
	 */
	private void loadFilterSettings(IMemento memento) {
		if (memento == null)
			return;
		Boolean andValue = memento.getBoolean(TAG_AND);
		if (andValue != null)
			setAndFilters(andValue.booleanValue());