The problem was that the used `Diary::diary_names()` iterator does not
call `unique()` on its output.
That decision was made because the return type would get more
complicated with that feature.
Now that rustc 1.26 with Impl Trait is out, we can refactor the return
types of these functions (so also with `Diary::diary_names()`) to
automatically do this.
This reverts commit b90abfb868.
Because `libimagcontact` is not based on `libimagentryref` anymore (as
of 2b10ab0b36), and thus does not put
pathes into the header, we can allow non-absolute pathes here.
The edit command of imag-diary gets removed by this patch.
The rationale is that imag-edit is way more powerful and thus, not every
other imag module should implement an edit command. Chaining
`imag-diary list` and `imag edit -I` is encouraged.
We still need the edit functionality in imag-diary, as `imag diary
create` shall spawn an editor, still. We only remove the ability for
editing of existing entries with this patch.
In case of auto-generating the file name, we should add an extension.
If we do not auto-generate the file name, we should warn that the
extension for the file is missing.
We should not depend on the version crate, as it is GPL licensed.
We removed the usage of this crate before, but it was still in the
Cargo.toml files (despite being used in the source).
