Added operator delete.
Bug Fix. Do not remove undefined variables from stack.


git-svn-id: http://yate.null.ro/svn/yate/trunk@5397 acf43c95-373e-0410-b603-e72c3f656dc1
Added possibility to extract a parameter from NamedList.


git-svn-id: http://yate.null.ro/svn/yate/trunk@5398 acf43c95-373e-0410-b603-e72c3f656dc1