According to relicensecheck Brad is OK with changing LGPLv2 to LGPLv2+,
which is required to be compatible with the LGPL-2.1-or-later licensed
source files.
We now support up to and including version 11 of the XCF format, earlier
it only supported version 1 (from 1997, according to the XCF spec).
Biggest difference seems to be that they changed to 64bit for offsets
from version 11 and upwards, otherwise it's mostly just newer enum
values and theoretically major stuff that we don't really need to care
about to get a thumbnail (e. g. linear vs. perceptual RGB).
We still don't support all features, but now it handles that more
gracefully and should at least create thumbnails that are usable. It
should also be easier to update in the future if/when there comes new
versions.
Also added a test file created with the latest version of Gimp
(2.10.18).
Reviewed By: aacid
Differential Revision: https://phabricator.kde.org/D25937
Frameworks have a convention of naming uninstalled headers in src/ with
a _p at the end of the name, to make it clear they are not part of the
API. None of the headers in KImageFormats are installed, so it is not
really necessary to follow this convention, but we follow it anyway for
the benefit of both humans and tools (like kapidox).
