Bug 314847 Command parameters are never cleared
bundles/org.eclipse.e4.core.commands/src/org/eclipse/e4/core/commands/internal/HandlerServiceImpl.java
final static String H_ID = "handler::"; 
	public final static String PARM_MAP = "parmMap::"; 
	final static String LOOKUP_HANDLER = "handler"; 
	public static Object lookUpHandler(IEclipseContext context, String commandId) {
		IEclipseContext current = context;
		IEclipseContext child = (IEclipseContext) current.getLocal(IContextConstants.ACTIVE_CHILD);
		while (child != null) {
			current = child;
			child = (IEclipseContext) current.getLocal(IContextConstants.ACTIVE_CHILD);
		}
		return current.get(H_ID + commandId);
	}
	private IEclipseContext context;
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.e4.core.commands.EHandlerService#activateHandler(java.lang.String,
	 * java.lang.Object)
	 */
	public void activateHandler(String commandId, Object handler) {
		String handlerId = H_ID + commandId;
		context.set(handlerId, handler);
	}
	/**
	 * @param command
	 */
	private void addParmsToContext(ParameterizedCommand command) {
		final Map parms = command.getParameterMap();
		Iterator i = parms.entrySet().iterator();