Even though it's not public yet (and won't really be for GIMP 3.0), I
created a new concept of "GIMP Extension" (.gex files) which bundles
various types of data for GIMP, such as plug-ins but also brushes and
other resources, themes, icons, etc.
Having 2 different concepts named the same is confusing, especially
since one of them is not really self-explaining IMO (why are "always-ON"
plug-ins called "extensions"?). So even though this is the older
concept, and since we are anyway massively breaking the API for GIMP
3.0, let's rename this older concept. "Persistent Plug-Ins" is much more
self-defining.
a9bc4c6c1b