Remove newtype struct auto-dereferencing method resolution

[brson]

This topic is sort of buried in #3534. Consider removing the auto-deref behavior on newtype structs. Specifically, auto-dereferencing method resolution. I have seen unexpected method checking errors because of it on multiple occasions, but have not seen it used effectively.

The use case I know for this feature is smart pointers, but as a solution for smart pointer dereferencing it is not useful because it allows for no additional state besides the contained value.

Simplifying method resolution is good.

[brson]

I still do not like this at all. Nominating.

[catamorphism]

1.0, backwards-compatible