Bug 78867 Using new registry API
Following some rework of the registry, please apply this patch to make use of the new method called getNamespace() on IConfigurationElement. This patch will convert most occurrences of: configurationElement.getDeclaringExtension().getNamespace() into configurationElement.getNamespace()
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/util/CoreUtility.java
* @param classAttribute the name of the attribute carrying the class
	 * @return the extension object
	 */
	public static Object createExtension(final IConfigurationElement element, final String classAttribute) throws CoreException {
		
		
		String pluginId = element.getDeclaringExtension().getNamespace();
		Bundle bundle = Platform.getBundle(pluginId);
		if (bundle != null && bundle.getState() == Bundle.ACTIVE ) {
			return element.createExecutableExtension(classAttribute);
		} else {
			final Object[] ret = new Object[1];
			final CoreException[] exc = new CoreException[1];
			BusyIndicator.showWhile(null, new Runnable() {
				public void run() {
					try {
						ret[0] = element.createExecutableExtension(classAttribute);
					} catch (CoreException e) {
						exc[0] = e;
					}
				}
			});
			if (exc[0] != null)
				throw exc[0];
			else
				return ret[0];
		}
	}	
}