Disable auto registration for base classes

[cllns]

Cleanup for #180 and #197.

We don't want the base classes to be auto_registered in the app's container, since they're meant to be used as parent classes, not used as instances directly.

[timriley]

Thanks for being conscientious and looping back to this, @cllns!

However, I think we're already in the clear here: all of the files you touch here are generated into db/ directories, and since db is in our default no_auto_register_paths, nothing in this directory will be auto-registered anyway.

And I don't think we should put these directives on files that are already excluded courtesy of their location, especially if it's not likely those files will ever move anywhere, since the unnecessary inclusion of the directive may confuse our users.

So I think we can close this one 😄

[cllns]

Oh sweet, I missed that! Thanks