Review necessity of the reference function.

[knutnergaard]

Ref the following post and issue #71:

          > What's the purpose then of the base.reference function and how would you prefer we annotate this?

Hmmmm. This is a really good question. I'm hesitant to change it because it may blow things up, but I'm 70% sure it won't. For now, let's do the following:

1. Open an issue for me to review the necessity of the reference function. Add a link to #71.
2. Delete the commented weakref code and add some documentation. Something like this:

This code returns a simple function that returns the given object. This is a backwards compatibility function that is under review. See (new issue number). We used to use weak references, but they proved problematic (see issue #71), so this function was put in place to make sure existing code continued to function. The need for it is questionable, so it may be deleted soon.

Does that work for everyone? I'd review it now but I don't trust my brain power to make such a big decision at the moment.

Originally posted by @typesupply in https://github.com/robotools/fontParts/issues/745#issuecomment-2391489355