Bug 190061 [Metadata] Update @since tags for new API
Patch to follow
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/Command.java
* command should print information to <code>System.out</code> when
	 * changing handlers.
	 */
	public static String DEBUG_HANDLERS_COMMAND_ID = null;
	/**
	 * The category to which this command belongs. This value should not be
	 * <code>null</code> unless the command is undefined.
	 */
	private Category category = null;
	/**
	 * A collection of objects listening to the execution of this command. This
	 * collection is <code>null</code> if there are no listeners.
	 */
	private transient ListenerList executionListeners = null;
	/**
	 * The handler currently associated with this command. This value may be
	 * <code>null</code> if there is no handler currently.
	 */
	private transient IHandler handler = null;
	/**
	 * The help context identifier for this command. This can be
	 * <code>null</code> if there is no help currently associated with the
	 * command.
	 * 
	 * @since 3.2
	 */
	private String helpContextId;
	/**
	 * The ordered array of parameters understood by this command. This value
	 * may be <code>null</code> if there are no parameters, or if the command