Methods from deref in rustdoc erroneously show static methods

An example (originally found in this [SO question](http://stackoverflow.com/questions/30362979/how-to-run-pathbufnew-with-an-argument)) is [PathBuf](http://doc.rust-lang.org/nightly/std/path/struct.PathBuf.html) - it shows a static method on `Path` in the "Methods from Deref" section, but naturally static methods can't be called through `Deref` since it requires having an object.
