In the various PDB transform functions, avoid erroneously creating
a floating selection when transforming the image mask, and rather
transform the mask normally.
Remove the special clipping-mode handling for channels throughout
the transform (and drawable-filter) code, and rather use
gimp_item_get_clip(), added in the previous commit, instead. As
mentioned in the previous commit, we only modify the clipping mode
in top-level code, while having lower-level code use the clipping
mode as-is. This not only hides the actual clipping-mode logic
from the transform code, but, in particular, allows code performing
transformation internally to use arbitrary clipping modes.
Also, this commit fixes a bunch of PDB bugs all over the place :)
We were only able to translate selections and layers (bot not channels
and paths) via the PDB, this new procedure fixes that. Deprecation of
old API and some more transform consistency to follow...
It never belonged inside "tools". Also rename its "pdb" subdirectory
to "groups". This had to happen before 2.10 so cherry-picking between
branches doesn't become a nightmare in the future.
Jehan