with window functions. Added the test case for it.
Also allowed to use aliases for set functions in partition and order lists
that are specified in window functions.
of the type SQL_I_List<ORDER> rather then the objects of this type.
It allows to replace easily one instance of such a list for another.
Besides it will facilitate to compare two lists if they originate from the
same window specification.
In fact any direct assignment for objects of the type SQL_I_List<ORDER>
was not valid.
