lib MDL-26458 adding unit tests to test cursors.  -added test with limits and order by with table aliases to test_get_records_sql()  -added test_recordset_locks_delete() and test_recordset_locks_update()  - added out of range limits test to test_get_records_sql()
lib MDL-26458 adding unit tests to test cursors.
 -added test with limits and order by with table aliases to test_get_records_sql()
 -added test_recordset_locks_delete() and test_recordset_locks_update()
 - added out of range limits test to test_get_records_sql()

dilawar/moodle