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/CommandManager.java
}
		if (buffer == null)
			return escapedText;
		return buffer.toString();
	}
	/**
	 * The map of category identifiers (<code>String</code>) to categories (
	 * <code>Category</code>). This collection may be empty, but it is never
	 * <code>null</code>.
	 */
	private final Map categoriesById = new HashMap();
	/**
	 * The set of identifiers for those categories that are defined. This value
	 * may be empty, but it is never <code>null</code>.
	 */
	private final Set definedCategoryIds = new HashSet();
	/**
	 * The set of identifiers for those command parameter types that are
	 * defined. This value may be empty, but it is never <code>null</code>.
	 * 
	 * @since 3.2
	 */
	private final Set definedParameterTypeIds = new HashSet();
	/**
	 * The execution listener for this command manager. This just forwards
	 * events from commands controlled by this manager to listeners on this
	 * manager.
	 */
	private IExecutionListener executionListener = null;
	/**