No More plugin_opts

I have removed the creation of the Model plugin_opts class, instance, and dataset methods. This probably won’t concern you unless you have a custom plugin you are keeping to yourself, as none of the built in plugins used these methods, and I couldn’t fine an existing external user either. It doesn’t appear that these methods were documented outside of the specs, so I doubt this will have a negative effect on anyone. However, if you are using one of the plugin_opts methods for an internal plugin, you’ll have to define the necessary plugin_opts method(s) in your plugin’s apply method after upgrading Sequel.