Fix EntitySet tests under L2SQL.
Fix EntitySet tests under L2SQL.

The EntitySet.Add() and EntitySet.IList_Add() were asserting information that
is clearly database specific (e.g. the ordering of Customers in the DB), and
wasn't important to the actual test.

Removing these extraneous asserts allow the tests to pass against
DbLinq.SqlServer_test and L2SQL.


vinodvar/dblinq,vinodvar/dblinq,Avira/dblinq,Avira/dblinq