"upgrade" failed on windows, because of lower_case_table_name.
This fix changes letters to lower case, not to depend on OS.
Note, this change does not affect coverage of
Bug N 17142 "Crash if create with encoded name",
which the test war originally written for.
upgrade.result, upgrade.test:
Adding test case.
table.cc:
Don't try to open a table with old-formatted name,
if the table name contains "@" character.
This is to avoid mixing two different names to each other.
Thanks Monty for suggesting this fix.