Use GTK3 Mono bindings

[alucryd]

This was most straightforward, checked mono_demo and it's working as expected.

AFAICT, Arch, Debian/Ubuntu and a few RPM distros already package those bindings, while others like Fedora, OpenSUSE and CentOS are still stuck with only the GTK2 bindings. The GTK3 bindings are still in beta state which explains why some distro won't provide them yet. Knowing that, are you keen on dropping GTK2, or would you rather check for glib-sharp-3.0 and fallback to glib-sharp-2.0?

[matttbe]

Hello Maxime,

Thank you for this patch! :-)

Here I see that you've changed the GLib Mono bindings, not the GTK ones (because GTK is not used in these interfaces).
In fact, I don't know what's the goal of glib-sharp-3.0. When looking at Ubuntu packages, I can see that libgtk3.0-cil has libglib3.0-cil in its dependences list but there is no 3.x versions for GLib. We should be able to use the latest version of GLib (2.xx) with both GTK2 and GTK3. I can also see that no applications are using libgtk3.0-cil or libglib3.0-cil except gtk-sharp3-examples.

To summary, the only thing that I want to know is: can we compile CDApplet.cs with glib-sharp-3.0 but still use glib-sharp-2.0 in the application which will use CDApplet.dll.
If yes, maybe it could be better to check in CMakeLists.txt if glib-sharp-3.0 is available and if not, use glib-sharp-2.0 :-)

[alucryd]

Hey, apologies for the delay.

Indeed, it seems that the API hasn't changed between versions 2 and 3 of the GLib bindings. As long as the application is using those bindings only, it shouldn't matter which of the glib-sharp is used to build CDApplet.dll, then a check for both in CMakeLists.txt is probably the better option. I updated my changes to do just that.