Since gtk Widgets are not Send, and the callbacks all run in the gtk
main loop, it *should* not be possible that 2 things try to access the
same widget at the same time.

Update links to new repo

See merge request !32

Thanks a lot to the diesel gittrer channel!

My PR for Channelinto_items() went through and a new rss
release in is already available!

It was only used to call the podcast.id() method. This allows EpisodeViewWidget
to be created whithout the need for a call to the database to get a Podcst
Object for each widget.

As logn we are not doing anything funny to bypass the borrow-checker,
we should not be able to touch gtk wigets from other threads anyway.

abc8fb98 uses an feature of rayon
that's behind a compile time flag.

`futures::stream::iter_ok` is so conviniet, why had None told me
about it before?

When iteration of data is finished, None will be returned and
the or_else() block will be executed. Now a callback can be
passed that will be executd when the iteration/loading finishes.

lazy_load_full is meant for siturations that you don't need
the constraisn of passing a single container parent and adding
a sigle widget to it.

Reimplemnted lazy_load on top of lazy_load_full.

If you clicked unsub, then undo and then the same show widget you
would navigated to the previous ShowWidget and the unsub button
would still be insensitive.