Bug 123040 [Commands] request: display help topic
I'm going to attach a patch to "command-ify" the opening of help topics. The command takes a parameter which is the href of a help topic. The default handler uses IWorkbenchHelpSystem.displayHelpResource(String) with the href parameter. If no parameter was given, the default handler calls IWorkbenchHelpSystem.displayHelp() instead to simply open the help system. Note that this looks like it should be opened against User Assistance, but the plugins that should be patched (I think) are org.eclipse.ui and org.eclipse.ui.workbench, so I opened against UI.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/ParameterizedCommand.java
* parameter is <code>null</code>.
	 * </p>
	 * <p>
	 * For example, the string shown below represents a serialized parameterized
	 * command that can be used to show the Resource perspective:
	 * </p>
	 * <p>
	 * <code>org.eclipse.ui.perspectives.showPerspective(org.eclipse.ui.perspectives.showPerspective.perspectiveId=org.eclipse.ui.resourcePerspective)</code>
	 * </p>
	 * <p>
	 * This example shows the more general form with multiple parameters,
	 * <code>null</code> value parameters, and escaped <code>=</code> in the
	 * third parameter value.
	 * </p>
	 * <p>
	 * <code>command.id(param1.id=value1,param2.id,param3.id=esc%=val3)</code>
	 * </p>
	 * 
	 * @return A string containing the escaped command id, parameter ids and
	 *         parameter values; never <code>null</code>.
	 * @see CommandManager#deserialize(String)
	 * @since 3.2
	 */
	public final String serialize() {
		final String escapedId = escape(getId());
		if ((parameterizations == null) || (parameterizations.length == 0)) {
			return escapedId;
		}
		final StringBuffer buffer = new StringBuffer(escapedId);
		buffer.append(CommandManager.PARAMETER_START_CHAR);