Added a more convenient XmlElement::findFirstChild and constified first parameter of findNextChild.


git-svn-id: http://yate.null.ro/svn/yate/trunk@5905 acf43c95-373e-0410-b603-e72c3f656dc1
Export the GSM MM reject causes dictionary.


git-svn-id: http://yate.null.ro/svn/yate/trunk@5906 acf43c95-373e-0410-b603-e72c3f656dc1