Combine tests and restore columns dropped by hstore testing

Disabling the hstore extension during testing created order dependent
test failures.
Merge pull request #9876 from macksmind/restore_cols_dropped_by_hstore_test

Restore columns dropped by hstore test
drop variable assignment in validations
Merge pull request #9945 from vipulnsward/drop_var_in_validations

Drop variable assignment in validations