Issue title: mootools-core-1.4.4 - fade out bug
 Issue body: Here is a simple test which shows that fade out/(0) instantly sets the opacity of the element to 0 while fade in/(1) works fine taking the default 500ms with the new core.

``` html


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

<title>fade test</title>


<script type="text/javascript" src="mootools-core-1.4.4-full-nocompat.js"></script>

<script type="text/javascript">
window.addEvent('domready',function() {

var slides = $('content');

$('fadeout').addEvent('click', function(){slides.fade(0)});

$('fadein').addEvent('click', function(){slides.fade(1)});

})
</script>

</head>
<body>

<div id='content'>

<img src="1.jpg"  alt="" />
<img src="2.jpg"  alt="" />

</div>

<input type="button" id="fadeout" name="fadeout" value="Fade Out" />
<input type="button" id="fadein" name="fadein" value="Fade In" />


</body>
</html>
```

 Comments: 
 Comment 0: This has been fixed in 1.4.5

{'source': 'GithubIssues', 'repo_name_with_owner': 'mootools/mootools-core', 'issue_id': 3387934, 'repo_stars': 2611.0}