Cleanup remaining warnings where possible

[sedwards]

This cleans up all of the remaining warnings we are able to while still leaving the deprecated gtk2 code enabled.

I am exploring what it would take to make a wrapper library and just backport the GtkCTree and CList functionality on to GTK3 and perhaps even GTK4. I am not a fan of those older Gtk2 functions, however the effort to port only to have them break something else by removing features is annoying.

Given how much they have neutered GTK, I don't really think it would be a bad idea to have this extra graphics layer wrapper we abstract away their changes if possible.

[sedwards]

I just saw there was a configure option for gtk warnings, so I am moving this back to Draft for the moment.

[wdlkmpx]

This is my gtk graphics layer https://github.com/wdlkmpx/wgtk/tree/master/0libwgtk

I currently use it with Xdialog (compiles with gtk1/2/3), the layer needs a lot of additions/improvements/work. But I have other things to do

When it comes to gtkgrid/table I was about to apply the layer to gftp, but I didn't

[wdlkmpx]

I don't think gftp will ever be ported to gtk4, I think I read somewhere that gtk4 introduced bugs in gtktreeview and similar widgets

GtkTreeView and GtkComboBox were deprecated in gtk 4.10, don't these guys realize that people need at least 20 years to master GtkTreeView

With my gtk layer, the code can be mostly gtk3 compatible without warnings, but some things probably require a completely different approach (i.e. the bookmark menu)

So in the end, gtk is a huge waste of time and deserves a painful death

[sedwards]

I've silenced some useless warnings unless one is looking for pain and misery of updating GTK code for the hell of it.