#13 xcf_masks are not loaded

[Kai-Uwe Behrmann]

images with layers and masks are saved.
After opening in filmgimp again they are empty.
Without masks this happens not so often.

on loading:
xcf_load_row: tags dont match for row
on showing:
** WARNING **: combine_areas: bad tags!

The layermanager shows all layers contain data
and masks are completely black.

Regards
Kai-Uwe