Looking at the documentation it is indeed red that should go
in the lowest bits and blue in the highest bits so just
reverse our code for red and blue.
We also update the version of our GIMP DDS plug-in,
this way we can catch and correct RGB10A2 images
written by older versions of our plug-in and correct
them.
Since older versions of our GIMP dds file exporter incorrectly
saved BC5 dds images with the red and green channels
swapped we should fix that. Since the exporter already
wrote the plug-ins version number and that it is written by
GIMP we can check for these incorrect images.
To enable that we increase the plug-ins revision in this
commit and swap red and green channels for images
that have an older version number and are of the
correct type.
