There is no need to filter for references in such a complicated way.
docker images already works if you just pass the image and tag as
an argument.
This caused problems if one was using podman with its docker-compatible
interface.
Previously podman would return the following error:
Error: cannot specify an image and a filter(s)
With this new method podman does not return an error anymore, causing
the image to not be redownloaded every time and it still works with
normal Docker.
Before this patch multiline warnings would appear in a single line with
'^@' as separator.
Now we use whitespace as separator to improve the appearance.
Also strip trailing whitespace, newlines, etc...
Fixes#3939
Magnus Groß