Bug 126414 [Commands] handlers: Provide help context ids
For commands and handlers to replace actions, they need to be capable of providing help context identifiers. For an example, see OpenResourceHandler in org.eclipse.ui.ide. This help context id will need to be definable through XML and through code.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/CommandEvent.java
/**
	 * Creates a new instance of this class.
	 * 
	 * @param command
	 *            the instance of the interface that changed.
	 * @param categoryChanged
	 *            <code>true</code>, iff the category property changed.
	 * @param definedChanged
	 *            <code>true</code>, iff the defined property changed.
	 * @param descriptionChanged
	 *            <code>true</code>, iff the description property changed.
	 * @param handledChanged
	 *            <code>true</code>, iff the handled property changed.
	 * @param nameChanged
	 *            <code>true</code>, iff the name property changed.
	 * @param parametersChanged
	 *            <code>true</code> if the parameters have changed;
	 *            <code>false</code> otherwise.
	 * @param returnTypeChanged
	 *            <code>true</code> iff the return type property changed;
	 *            <code>false</code> otherwise.
	 * @since 3.2
	 */
	public CommandEvent(final Command command, final boolean categoryChanged,
			final boolean definedChanged, final boolean descriptionChanged,
			final boolean handledChanged, final boolean nameChanged,
			final boolean parametersChanged, final boolean returnTypeChanged) {
		super(definedChanged, descriptionChanged, nameChanged);
		if (command == null)