single `shims` function calls `move_to` and `Getattr`

[mmckerns]

The @move_to decorator must be paired with the overloading by the Getattr later in the shims module. It seems like with a little redesign, this could be consolidated to a single function / decorator.

[mmckerns]

See #443 for reference. Tag: @anivegesana

[anivegesana]

This construct tries to give a base definition for a function that will be or was defined differently in another version of Python or dill. Because of this, should we just call both move_to and Getattr put together soft_def?

[mmckerns]

I was thinking about something along those lines, yes.

[anivegesana]

Do you do think there is any value in having a separate Getattr and move_to function along with a soft_def function? I guess we could add them back in if they are found to be useful for something else.

[mmckerns]

It doesn't hurt to keep them available as separate functions.