Identify weak XML parser properties that could lead to XXE

[h3xstream]

Taken from SonarQube mailinglist : https://groups.google.com/forum/#!topic/sonarqube/M-u9qObOWtU

public String parseXML(InputStream input, XMLStreamReader r) {
 StringBuilder content = new StringBuilder();
 XMLInputFactory factory = XMLInputFactory.newFactory();
 factory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, true);
 factory.setProperty(XMLInputFactory.SUPPORT_DTD, true);
 XMLStreamReader reader = r;

should raise two issues, because the properties from XMLInputFactory are both set true, but there are
no issues created, see a good explanation on Stackoverflow

[h3xstream]

Duplicate #191