Output reexported symbols from other crates

[gnarea]

Expected behaviour

We should output namespaces and their respective symbols from other crates, when the current crate reexports such symbols.

Current behaviour

Simple (e.g. pub use another_crate::Foo) and aliased (e.g. pub use another_crate::Foo as Bar) reexports are output as is. Only the pub use ... statement is output.

Wildcards are skipped.