old compability

1.9.3 (main):0 > 'tw_cli_3'.classify
=> "TwCli3"
1.9.3 (main):0 > 'TwCli_3'.underscore
=> "tw_cli_3"
1.9.3 (main):0 > 'TwCli_3'.underscore.classify
=> "TwCli3"
1.9.3 (main):0 > 'TwCli_3'.underscore.classify.underscore
=> "tw_cli3"