Gtkmm IconTheme demo

[Kjell Ahlstedt <kjell ahlstedt bredband net>]

A recent commit message in gtkmm says

Demo: IconTheme: Don't use deprecated builtin-icon API.
By the way, there is now a separate icon browser in gtk+'s demos/. Maybe we should create a version of that instead. I think this C++ code never corresponded to anything in the GTK+ demo.

I made the IconTheme as a replacement for the StockBrowser demo when stock icons were deprecated. Gtk+'s demos/icon_browser looks better, and it starts up in a reasonable amount of time (the IconTheme demo does not). But I don't understand why it's a separate program. If I'd make a C++ version of gtk+'s icon browser, I'd prefer to make it run under gtkmm/demos/gtk-demo/gtkmm-demo, like most demo programs.

Why do we have both gtkmm/demos/pixbuf-demo.cc and gtkmm/demos/gtk-demo/example_pixbufs.cc?