Xml parser should handle entities defined in doctype

The following xml:

 
<?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE test [
<!ENTITY foo "&#x160;">
]>
<b>&foo;</b>

displays "null" instead of a space.

We need to handle XmlPullParser.DOCDECL in AbstractXmlParser#parseXml(XmlPullParser, Sink)