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
private String attribute;
	private String markerType;
	private String defaultGroupingEntry;
	private IConfigurationElement element;
	
	private Collection groups = new HashSet();
	/**
	 * Create a new instance of the receiver for the given attribute on the
	 * markerType with an optional default grouping.
	 * 
	 * @param attributeId