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/views/markers/internal/AttributeMarkerGrouping.java
* @param markerId
	 * @param defaultEntry
	 * @param configElement
	 */
	public AttributeMarkerGrouping(String attributeId, String markerId,
			String defaultEntry, IConfigurationElement configElement) {
		attribute = attributeId;
		markerType = markerId;
		defaultGroupingEntry = defaultEntry;
		element = configElement;
	}
	/**
	 * Return the id of the default grouping.
	 * @return String or <code>null</code> if it is not defined.
	 */
	public String getDefaultGroupingEntry() {
		return defaultGroupingEntry;
	}
	/**
	 * Return the id of the marker type for this type.
	 * @return String
	 */
	public String getMarkerType() {
		return markerType;
	}
	/**
	 * Return the name of the attribute for the receiver.
	 * @return String
	 */
	public String getAttribute() {