Bug 279452 [Compatibility] Parameterized command mechanism support
Parameterized commands like showView need to be able to access their parameters (like the view ID) PW
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/HandlerTest.java
defineCommands(appContext);
		TestHandler handler = new TestHandler(true, HELP_COMMAND_ID);
		EHandlerService service = (EHandlerService) appContext
				.get(EHandlerService.class.getName());
		service.activateHandler(HELP_COMMAND_ID, handler);
		Command command = (Command) appContext.get(HELP_COMMAND_ID);
		assertEquals(HELP_COMMAND_ID, command.getId());
		assertEquals(HELP_COMMAND_ID, service.executeHandler(HELP_COMMAND_ID));
		assertTrue(handler.ran);
		assertNull(service.executeHandler(HELP_COMMAND1_ID));
	}
	public void testTwoCommands() throws Exception {
		IEclipseContext appContext = createGlobalContext();
		defineCommands(appContext);
		EHandlerService service = (EHandlerService) appContext
				.get(EHandlerService.class.getName());
		TestHandler handler = new TestHandler(true, HELP_COMMAND_ID);
		service.activateHandler(HELP_COMMAND_ID, handler);
		TestHandler handler1 = new TestHandler(false, HELP_COMMAND1_ID);
		service.activateHandler(HELP_COMMAND1_ID, handler1);
		assertEquals(HELP_COMMAND_ID, service.executeHandler(HELP_COMMAND_ID));
		assertNull(service.executeHandler(HELP_COMMAND1_ID));
		assertFalse(handler1.ran);
		handler1.canRun = true;
		assertEquals(HELP_COMMAND1_ID, service.executeHandler(HELP_COMMAND1_ID));
		assertTrue(handler1.ran);
	}
	public void testTwoHandlers() throws Exception {
		IEclipseContext appContext = createGlobalContext();
		defineCommands(appContext);