Renamed ActiveModel::GlobalIdentification => GlobalID::Identification an...

...d ActiveModel::GlobalLocator => GlobalID::Locator
This is intentional. Bundler autorequires the lib/ file with the same name as the gem, so `lib/globalid.rb`

People who require `global_id` directly are in libraries and don't need to attempt to load the Railtie.

This is important when a lib depends on globalid and that lib gets used in a Rails app that isn't using globalid. Now they have a railtie they didn't expect.