In the previous versions, the sink (where the entries should be written
to) was not passed.
This did conflict with the libimagrt holding the stdout/stderr handles,
because it automatically writes to stdout (which we don't want to do in
some cases).
Passing the sink is way nicer. This patch changes libimagentryview so
that the sink is passed to the viewer.
This patch removes unused crate imports reported by newer rust versions.
Some crates were only required for tests, some only for tests with
macro_import - these things were fixed with feature gates.
