Metadata lost in nested elementwise operations

[vsaase]

Hi,
check this out:

using ImageMetadata
a = ImageMeta(ones(10,10))
a["asdf"] = 1
b = ImageMeta(ones(10,10))
(a.+b)["asdf"] == 1 #true
(log.(a))["asdf"] == 1 #true
(log.(a.+b))["asdf"] == 1 #KeyError: key "asdf" not found
(b.+a)["asdf"] == 1 #KeyError: key "asdf" not found

Metadata should not be lost without a warning
Also I think a big point in using ImageMetadata is that metadata is kept around as much as possible, so shouldn't it somehow be more intuitive than just keeping the metadata of the first ImageMeta in the expression?