Bug 221521 [Markers] New markers API needs to be pared down
We have too much API in some of the new classes and they can be moved to internals
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerSupportRegistry.java
/**
	 * Process the extension and register the result with the tracker. Fill the
	 * map of groupingEntries and attribueMappings processed for post
	 * processing.
	 * 
	 * @param tracker
	 * @param extension
	 * @param groupIDsToEntries
	 *            Mapping of group names to the markerGroupingEntries registered
	 *            for them
	 * @param entryIDsToEntries
	 *            Mapping of entry ids to entries
	 * @param attributeMappings
	 *            the markerAttributeGroupings found
	 * @param generatorExtensions
	 *            the markerContentGenerator extensions keyed on group id
	 * @see #postProcessExtensions(Map, Map, Collection, Map)
	 */
	private void processExtension(IExtensionTracker tracker,
			IExtension extension, Map groupIDsToEntries, Map entryIDsToEntries,
			Collection attributeMappings, Map generatorExtensions) {
		IConfigurationElement[] elements = extension.getConfigurationElements();
		for (int j = 0; j < elements.length; j++) {
			IConfigurationElement element = elements[j];
			if (element.getName().equals(PROBLEM_FILTER)) {
				ProblemFilter filter = newFilter(element);
				registeredFilters.put(filter.getId(), filter);
				tracker.registerObject(extension, filter,
						IExtensionTracker.REF_STRONG);
				continue;