app: edit the bucket fill tool options with new line art options.
I have not added all the options for this new tool yet, but this sets the base. I also added a bit of TODO for several places where we need to make it settable, in particular the fuzzy select tool, but also simply PDB calls (this will need to be a PDB context settings. Maybe also I will want to make some LineArtOptions struct in order not to have infinite list of parameters to functions. And at some point, it may also be worth splitting a bit process with other type of selection/fill (since they barely share any settings anyway). Finally I take the opportunity to document a little more the parameters to gimp_lineart_close(), which can still be improved later (I should have documented these straight away when I re-implemented this all from G'Mic code, as I am a bit fuzzy on some details now and will need to re-understand code).
Showing with 199 additions and 54 deletions