Since meson 0.43.0 (below our current requirement), 'symbol_prefix'
argument of gnome.generate_gir() allows an ordered list. If I prepend
'gimp_ui', it makes any gimp_ui_*() function to not start with 'ui_'.
In particular, GimpUi.ui_init() becomes GimpUi.init() which is much less
redundant.
Oups, I left the plug-in as Python 2. This was still a good
proof-of-concept that GIMP 3 will support as well Python 2 and Python 3
(even though Python 2 is end-of-life soon anyway).
This first version will just offset by 1 in interactive mode, by
default. The GIMP 2 version used to have a GUI, but it was not created
by the plug-in itself. I am guessing that maybe our Python wrapper used
to create GUI by default.
If so, this will have to change. Python plug-ins will be responsible of
their own GUI, just like C plug-ins.
