Setting current item via ItemInterface->setCurrent()

Allows to make latte submenu like this:

```tpl
{block #submenu}
	{foreach $presenter['menu']->getRoot()->getChildren() as $item}
		{if $item->isCurrent()}
			{* this works nicely in the first level *}
			{control menu:subMenu, path => $item->getName()}
			{breakIf true}
		{/if}
	{/foreach}
{/block}
```

Without setting `$item->setCurrent(true OR false)` in the edited files (Voter, Matcher) would the query `isCurrent()` return always NULL on any item of the menu.