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
static final char PARAMETER_END_CHAR = ')';
	/**
	 * The character that separators parameters from each other.
	 */
	static final char PARAMETER_SEPARATOR_CHAR = ',';
	/**
	 * The character that indicates the start of a list of parameters.
	 */
	static final char PARAMETER_START_CHAR = '(';
	/**
	 * Unescapes special characters in the command id, parameter ids and
	 * parameter values for {@link #deserialize()}. The special characters
	 * {@link #PARAMETER_START_CHAR}, {@link #PARAMETER_END_CHAR},
	 * {@link #ID_VALUE_CHAR}, {@link #PARAMETER_SEPARATOR_CHAR} and
	 * {@link #ESCAPE_CHAR} are escaped by prepending an {@link #ESCAPE_CHAR}
	 * character.
	 * 
	 * @param escapedText
	 *            a <code>String</code> that may contain escaped special
	 *            characters for command serialization.
	 * @return a <code>String</code> representing <code>escapedText</code>
	 *         with any escaped characters replaced by their literal values
	 * @throws SerializationException
	 *             if <code>escapedText</code> contains an invalid escape
	 *             sequence
	 * @see ParameterizedCommand#escape(String)
	 * @since 3.2
	 */
	private static final String unescape(final String escapedText)
			throws SerializationException {