pushstream.js Utils.isCrossDomainUrl bugfix for IE

Hi, wandenberg

Current code for parsing url:
```javascript
var parser = document.createElement('a');
parser.href = url; 
```

If url does not contains port, for example "**http://test.com**", IE behaves differently then other browsers.

Browser | location.port | parser.port
---------- | ---------------- | --------------
Chrome 39 |       ''             | ''
Firefox 34 |       ''             | ''
Opera 12.16 |       ''             | ''
IE9        |        ''             | '80'
IE 11     |        ''             | '80' 

normalizePort() fix that for http and https protocols.