It appears to be some internal format of xview, although I cannot find
any mention of such a thing on the internet. There does not appear to
be any sort of mime type to associate with this file format, either.
Therefore, I think it is reasonable to declare it obsolete.
REVIEW: 115768
Two main tests: read the file and compare to a given image (loaded from
png), and write a file out and compare to a previously-written image.
The write test in particular is kind of fragile, but it should help
catch some errors where a code change was not intended to affect the
output of the plugin.
Tests are included for all the writable formats, as well as every
readable format that GIMP can write to (and so I could easily get an
example of).
REVIEW: 115430
