Bug 214648 [Markers] AttributeMarkerGroupings and GroupingEntries not being cleaned up on removal
We are still leaving the references to AttributeMarkerGroupings and GroupingEntries when we unload
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerSupportRegistry.java
* 
	 * @param element
	 *            the filter element
	 * @return ProblemFilter
	 */
	private ProblemFilter newFilter(IConfigurationElement element) {
		ProblemFilter filter = new ProblemFilter(element
				.getAttribute(MarkerSupportConstants.ATTRIBUTE_NAME));
		filter.createContributionFrom(element);
		String enabledValue = element.getAttribute(ENABLED);
		filter.setEnabled(enabledValue == null
				|| Boolean.valueOf(enabledValue).booleanValue());
		int scopeValue = getScopeValue(element);
		if (scopeValue >= 0) {
			filter.setOnResource(scopeValue);
		}
		String description = element.getAttribute(DESCRIPTION);
		if (description != null) {
			boolean contains = true;
			if (description.charAt(0) == '!') {
				description = description.substring(1, description.length());
				contains = false;
			}
			filter.setContains(contains);
			filter.setDescription(description);
		}
		int severityValue = getSeverityValue(element);
		if (severityValue > 0) {
			filter.setSelectBySeverity(true);
			filter.setSeverity(severityValue);