introduces XmlContainerElement to ease searching for child elements and moves XmlHelper to xml package because it is only needed for xml handling

src/main/java/de/thedevstack/conversationsplus/xml/Element.java

@@ -6,7 +6,6 @@ import java.util.List;
 
 import de.thedevstack.android.logcat.Logging;
 import de.thedevstack.conversationsplus.Config;
-import de.thedevstack.conversationsplus.utils.XmlHelper;
 import de.thedevstack.conversationsplus.xmpp.jid.InvalidJidException;
 import de.thedevstack.conversationsplus.xmpp.jid.Jid;
 
@@ -75,6 +74,11 @@ public class Element {
 		return null;
 	}
 
+    public Element findChild(XmlElementContainer container) {
+	    Element element = container.getXmlElement();
+        return findChild(element.getName(), element.getNamespace());
+    }
+
 	public String findChildContent(String name, String xmlns) {
 		Element element = findChild(name,xmlns);
 		return element == null ? null : element.getContent();
@@ -88,6 +92,11 @@ public class Element {
 		return findChild(name, xmlns) != null;
 	}
 
+	public boolean hasChild(XmlElementContainer container) {
+        Element element = container.getXmlElement();
+	    return hasChild(element.getName(), element.getNamespace());
+    }
+
 	public List<Element> getChildren() {
 		return this.children;
 	}

src/main/java/de/thedevstack/conversationsplus/xml/Tag.java

@@ -5,8 +5,6 @@ import java.util.Iterator;
 import java.util.Map.Entry;
 import java.util.Set;
 
-import de.thedevstack.conversationsplus.utils.XmlHelper;
-
 public class Tag {
 	public static final int NO = -1;
 	public static final int START = 0;

src/main/java/de/thedevstack/conversationsplus/xml/XmlElementContainer.java

@@ -0,0 +1,7 @@
+package de.thedevstack.conversationsplus.xml;
+
+/**
+ */
+public interface XmlElementContainer {
+    Element getXmlElement();
+}