add namespaced entity support

When using namespaced models you need to make sure to chop off the namespace portion of the entity class name before you can evaluate it into method names. I know that you are currently refactoring to use the Entity class making the code below much cleaner. This code can be reduced to a single line in the entity.name function there.
I am not sure about 'last' - this can cause problems when there is two models with same name in different namespaces. Maybe, it's better to do `.join('_')` instead?