Bug 205049 Other plug-ins should be able to define default content generator
Currently only the content generator can define which plug-ins it can be the default for - we need a way for plug-ins to refer back to the marker support for thier own generator.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerSupportRegistry.java
IDEWorkbenchPlugin.log(NLS.bind(
							"Reference to invalid markerGroupingEntry {0}",
							defaultEntryId));
				}
			}
			IConfigurationElement[] mappings = next.getElement().getChildren(
					ATTRIBUTE_MAPPING);
			for (int i = 0; i < mappings.length; i++) {
				String entryId = mappings[i]
						.getAttribute(MARKER_GROUPING_ENTRY);
				if (markerGroupingEntries.containsKey(entryId)) {
					MarkerGroupingEntry entry = (MarkerGroupingEntry) markerGroupingEntries
							.get(entryId);
					entry.mapAttribute(next.getMarkerType(), next
							.getAttribute(), mappings[i].getAttribute(VALUE));
				} else {
					IDEWorkbenchPlugin.log(NLS.bind(
							"Reference to invaild markerGroupingEntry {0}", 
							defaultEntryId));
				}
			}
		}
	}
	/**
	 * Get the markerTypes defined in element.
	 * 
	 * @param element
	 * @return String[]
	 */
	private String[] getMarkerTypes(IConfigurationElement element) {