Bug 139986 [CommonNavigator] Convert catch(Error/Throwable) to SafeRunner
In several places the CN framework uses catch(Error/Throwable) to ensure that code does not bring the framework down. Change these to use SafeRunner.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/extensions/NavigatorContentDescriptor.java
if (children.length == 1) {
				enablement = new CustomAndExpression(children[0]);
			} else {
				throw new WorkbenchException(NLS.bind(
						CommonNavigatorMessages.Attribute_Missing_Warning,
						new Object[] {
								TAG_TRIGGER_POINTS,
								id,
								configElement.getDeclaringExtension()
										.getNamespaceIdentifier() }));
			}
			children = configElement.getChildren(TAG_POSSIBLE_CHILDREN);
			if (children.length == 1) {
				possibleChildren = new CustomAndExpression(children[0]);
			} else if(children.length > 1){
				throw new WorkbenchException(NLS.bind(
						CommonNavigatorMessages.Attribute_Missing_Warning,
						new Object[] {
								TAG_POSSIBLE_CHILDREN,
								id,
								configElement.getDeclaringExtension()
										.getNamespaceIdentifier() }));
			}
		} else if (children.length == 1) {
			try {
				enablement = ElementHandler.getDefault().create(
						ExpressionConverter.getDefault(), children[0]);
			} catch (CoreException e) {
				NavigatorPlugin.log(IStatus.ERROR, 0, e.getMessage(), e);
			}